You're not showing yet at 6 weeks pregnant, but your little baby is growing strong. At pregnancy week 6, your baby may measure around 0.25 inches, or approximately 6mm. You can compare you baby's overall size to the size of a Sesame seed!
At 6 weeks pregnant, the average fetal heartbeat is between 100 and 140 beats per minute. Blood may start circulating throughout your baby's body this week. Your doctor or healthcare provider may be able to see the first heartbeats using an ultrasound, though it may still be a few weeks before the heartbeat is detectable via a Doppler device.
Your baby's face is developing at 6 weeks pregnant. Dark spots (which will eventually become his or her eyes) have formed on the side of the head, and there are small pits on the side of your baby's head where the ears will develop.
At 6 weeks pregnant, your baby's placenta is developing and won't be ready to take over its role for a few more weeks. Until the placenta is mature enough, the yolk sac (a balloon-like structure that is as big as your baby) is providing your baby with his or her nourishment. The yolk sac will start to disappear completely when the placenta is ready – around 9 or 10 weeks of gestation.
At this point in fetal development, your baby's hands and feet are connected with a layer of webbing. They don't be separate and distinct for several more weeks.
By 6 weeks pregnant, your little one has a curved "tail," which makes him or her look like a tadpole. This "tail" will eventually form the spinal column, and it will disappear once the spine straightens.
From pregnancy week 6 onward, your baby is undergoing dramatic change. He or she is developing all of his or her major organs (heart, lungs, brains, liver, stomach, etc.).
First Heartbeat During Pregnancy
At 6 weeks pregnant, your baby's little heart is beating strong - 100 to 140 beats/minute. (Your baby's heart first started beating at 5 weeks pregnant). However, since your little bundle of joy is so small right now, your doctor or caregiver won't be able to pick up the first fetal heartbeat and let you hear it with a Doppler ultrasound for a few more weeks.
For most women, they don't hear their baby's heartbeat for the first time until 12 weeks pregnant. But if you have a transvaginal ultrasound at 6 weeks, you should be able to see your baby's heartbeating.
At 6 weeks pregnant, your waist will start to become thicker, particularly if this is not your first pregnancy. Your uterus will also be changing in size now and throughout your pregnancy.
Spotting may or may not occur in the early weeks of pregnancy. It is usually nothing to worry about, however you should always call your healthcare practitioner to report any unusual bleeding, as it may be a sign of impending miscarriage or some other problem.
By pregnancy at 6 weeks, your uterus is probably about the size of a plum and your breasts are probably getting quite tender. Some women even find the sensation of their shirt rubbing against their breasts uncomfortable. At some point in pregnancy, your areolas or the dark area surrounding your nipple will start to darken. Physicians aren't 100% sure why this occurs, though some believe that the darkening helps the baby find their food source that much faster after birth!
At 6 weeks pregnant, you probably haven't actually started showing yet, though you will be able to detect subtle changes in your body. Your jeans may start to fit less comfortably around the midsection. It will be quite some time, however, before you will actually need to purchase maternity clothes.
One thing you might opt to do is to extend the period of time you wear ordinary clothes. You may want to invest in one or two pairs of pants that are a size bigger than your normal clothing. Belly belts are another option. These allow you to continue to wear your pre-pregnancy pants as your waistline expands.
At 6 weeks pregnant, you may have already experienced a few early pregnancy symptoms, such as tender and sore breasts, nausea (morning sickness), frequent urination, headaches, and mood swings and irritability. Your pregnancy symptoms at 6 weeks might be mild or they can be severe.
Sore and tender breasts are one of the first pregnancy symptoms you may experience, and it's caused by hormonal changes preparing your breasts ready for breastfeeding. Breast tenderness can occur as early as 4 or 6 weeks pregnant, and it can last throughout your first trimester. Don't be surprised if your breasts grow in size too.
To cope with your growing, tender breasts, make sure that you find a supportive maternity bra. You probably want to stay away from any bras with underwires (they're not supportive enough when you're pregnant). Even at 6 weeks pregnant, choosing a maternity bra is a good choice, since they have extra clasps in the back that accommodate your breast growth.
Fatigue is another pregnancy symptom to expect at 6 weeks pregnant and throughout your first trimester. Your exhaustion is also due to hormonal changes, especially the dramatic increase in progesterone. If you're also struggling with morning sickness and frequent urination, you will be even more tired. Not to worry – fatigue tends to go away in the second trimester. (But it will come back in the final weeks of pregnancy.)
Nausea and vomiting (also called morning sickness) is a hallmark of the first trimester. Your nausea might begin at 6 weeks pregnant, and it will get worse in the next month. You may even experience bouts of vomiting. You can also blame raging hormones for the nausea and vomiting that you're experiencing at 6 weeks pregnant. Fortunately, like nausea, morning sickness tends to abate by the end of your first trimester. (Only a small percentage of pregnant women will stay nauseous until they deliver.)
Mood swings typically appear at 6 weeks pregnant. Hormonal changes that occur in pregnancy can affect the level of neurotransmitters in your brain, and this can really cause you to experience heightened emotions. Plus, if you're struggling with other common pregnancy symptoms at 6 weeks pregnant, this can also have a negative effect on your mood. Your moodiness will ease up after 14 weeks pregnant. (The second trimester gives you relief from many of your first trimester discomforts.)
You may have gained another pound by now. Your weight gain at 6 weeks pregnant is probably between one or two pounds. Some women will be immediately aware of this slight weight gain; other pregnant women are too consumed with their pregnancy symptoms at 6 weeks pregnant.
If you’re suffering from morning sickness, especially if you’re vomiting a lot, you may have a hard time gaining weight. Try not to stress out. Some women gain their pregnancy pounds slower than others, and this is absolutely normal. You have ample time to gain the recommended 25 to 35 pounds for the average-sized woman.
You may be in the throws of morning sickness by 6 weeks pregnant. Morning sickness during pregnancy is perfectly normal, though some women experience a severe form of morning sickness called hyperemesis gravidarum. This is a pregnancy complication characterized by nausea and vomiting that is so severe that you may require hospitalization. Women affected by hyperemesis gravidarum may experience dehydration, electrolyte deficiencies, and higher weight loss than normal. The common symptoms include rapid weight loss, a fast heartbeat, weakness, and frequent vomiting.
The exact cause of this condition is unknown, though some studies suggest that younger maternal age, obesity and first time pregnancy are potential risk factors for the condition. Typically hospitalization will be necessary to help restore fluids that you are losing through vomiting to help replace electrolytes. Your healthcare provider may also have to provide hyperalimentation, a procedure in which you will receive nutrients and vitamins through an IV line.
Your doctor may recommend additional nutritional or vitamin supplementation after your hospitalization to ensure that you are able to store up an adequate number of nutrients for your baby. Normally, this condition will not have any ill effects on your baby once it is treated properly.
By 6 weeks pregnant, you may start putting on some weight. Women who do not have severe morning sickness often realize they've gained 1 to 5 or more pounds during their first trimester.
Many women believe that they should eat for two when pregnant. Realistically speaking, your body actually does not require additional calories until about the second trimester of pregnancy, when you should be consuming about 300 additional calories per day. 300 calories does not amount to much. One bagel may have as much as 300 calories. Many pregnant women go overboard, and consume an excess of 500 or more calories each day.
You will find that as your morning sickness subsides, your appetite will increase. The best thing you can do to help nourish your baby and curb your appetite is to eat several small or mini meals each day. This can actually help morning sickness as well, as morning sickness is frequently much worse on an empty stomach.
Be sure that when you are eating those 300 additional calories, you make healthful selections and eat a healthy pregnancy diet. Fruits, nuts, yogurt, and other healthy foods will not only help combat cravings, but they will also provide your developing baby with much needed nutrients. High fiber foods also help combat constipation, a common side effect of pregnancy. Fiber helps you feel full longer, and it helps your digestive tract function more smoothly during pregnancy.
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At 6 weeks pregnant, your waist will start to become thicker, particularly if this is not your first pregnancy. Your uterus will also be changing in size now and throughout your pregnancy. 
At 6 weeks pregnant, you may have already experienced a few early pregnancy symptoms, such as tender and sore breasts, nausea (morning sickness), frequent urination, headaches, and mood swings and irritability. Your pregnancy symptoms at 6 weeks might be mild or they can be severe. 
You may be in the throws of morning sickness by 6 weeks pregnant. Morning sickness during pregnancy is perfectly normal, though some women experience a severe form of morning sickness called 
