1 Week Pregnant

Learn what's happening in week 1 and 2 of pregnancy, and find out how your baby is developing.

It is highly unlikely you even know you are pregnant at this point, but there are many things going on with you and your baby.

Even though there's no baby in the 1st week of pregnancy, there are millions of sperm eagerly swimming upstream towards the fallopian tubes on their mission to fertilize the anxious egg. In weeks one and two, your body is working really hard to prepare for the ovulation process. Your uterus is preparing for the arrival of the fertilized egg, even though you won't know for sure if the egg was successfully fertilized until next month.

For most women, the first week of pregnancy can go unnoticed. Many women have variable monthly cycles and they are unable to notice the signs of being pregnant. Though there aren't any obvious early signs of pregnancy at this point, there are a few common symptoms such as fatigue, mood swings, constipation, and frequent urination. However, many women mistake these first symptoms of pregnancy for PMS symptoms and don't realize they are pregnant.

What happens in your body in pregnancy weeks 1 and 2?

1 Week Pregnant

You probably don't even know you're pregnant yet, but you're well on your way. Your conception date is two weeks after the last day of your last menstrual period.

Because of how pregnancy is calculated, at this stage (week one in pregnancy), you are actually already considered to be one month pregnant.

Most tests can't determine whether or not you're pregnant in the first two weeks of pregnancy. You won't notice anything strange yet, but if you're trying to conceive make sure to stay away from alcohol and smoking and start taking prenatal vitamins.

Changes in Your Body at 1 Week Pregnant

There are no noticeable physical changes during the first week of pregnancy. However, many internal changes occur and some of the most common symptoms of pregnancy include tender breasts, morning sickness, fatigue, constipation, gas, and mood swings. These symptoms appear as a result of the hormonal changes and are different for each woman. Although some women will have these pregnancy symptoms at 2 weeks, most of them will feel the changes in the third or fourth week.

Your Baby at 1 and 2 Weeks of Pregnancy

2 Weeks Pregnant

During the first week of pregnancy, there's no major development of your baby. The egg leaves the ovary and travels to the fallopian tubes and you're not actually pregnant at this time. Conception happens two weeks after your period ends. However, this week is part of the pregnancy calendar in order to help doctors calculate the first day of a woman's last menstrual cycle.

During the first week, the baby is called a blastocyte. The outer part of the blastocyte eventually forms the placenta, and the inner part becomes an embryo during the second week of pregnancy.

If more than one egg is released and fertilized, you may have multiple zygotes. The zygotes have 46 chromosomes that contain genetic material which will determine the baby’s sex, features, hair color, skin color, eye color, and height.

The two most important chromosomes are the X and the Y chromosomes because they will determine the baby's sex. If the sperm fertilizes the egg with a Y chromosome, you'll have a boy, but if it's an X chromosome, you'll have a girl.

In week two, the baby is now called an embryo that divides into three separate layers of cells. The internal layer (endoderm) is essential in forming the digestive system, the respiratory tract which includes the pancreas, liver, thyroid, and thymus, as well as the urinary tract. The middle layer (mesoderm) will form bones, circulatory system, cartilage, muscles, inner skin layer, and reproductive system. The outer layer (ectoderm) will become the nervous system, the lining of the mouth, and baby’s skin, hair, and nails.

During week two of pregnancy, the embryo is just floating within the uterus, protected by the secretions of the uterus lining. At this point, your baby is still very small - only 1 to 2 mm long.

Pregnancy Week 1 Tips

If you're trying to conceive, the first week will be one of anticipation and joy. If you've been monitoring your basal body temperature every morning, you will notice that your temperature remains elevated beyond day 16 of your Luteal Phase. This is obviously one of the first symptoms of pregnancy at 1 week.

Getting all the right vitamins and minerals is important right now. Even if you haven't done a positive pregnancy test yet, it is recommended that you take folic acid supplements and multivitamin to protect your unborn baby from certain birth defects.

Increased doses of folic acid are essential when you're trying to get pregnant and in early pregnancy. Your supplements should contain iron, calcium, and Vitamin B12. Quit bad habits such as smoking and drinking. This is important to a healthy pregnancy and a healthy baby. Change your eating habits - your diet should include lots of fruits and vegetables.