The First Trimester of Pregnancy Duration is from Week 1 to Week 12. There are 40 weeks (or 280 days) in a pregnancy. The doctor will calculate your due date from the first day of your last period. This is a general practice everywhere.

Physical Changes During The First Trimester of Pregnancy

Every Woman will undergo some major Physical Body Changes. 

• You may feel Nausea with or without vomiting.
• Breast Tenderness
• Mood swings.
• Frequent Urination
• Your Breast will start preparing for the milk.
• Heaviness in the body.
• Heartburn and Constipation.
• Food cravings 
• Fatigue more.

The First Trimester of Pregnancy

Week by Week

0-2 Weeks

• In the first 2 weeks, you’re not pregnant. Your body is preparing for ovulation (releasing an egg from one of your ovaries).
• After ovulation, 5 to 6 days later, the fertilized egg burrows into the womb’s lining, and it is called implantation. Congratulation, now you’re Pregnant.

Week 3

• Around the 3 weeks, you will find out that you have missed the period. Your due date for the period does not arrive.
• It is the time when you can take Home Pregnancy Test or can contact the doctor to confirm the News. Your doctor will advise you to go for HCG Pregnancy Test and maybe a few more tests as per your medical history.
• These pre-pregnancy pregnancies are very important to understand the cruciality of your pregnancy. The doctor will advise you to take a folic acid supplement, vitamin D supplement, and other supplements per your condition.
• This is a time your should start eating healthy foods and stop all your bad habits like smoking, drinking, heavy weight lifting, etc.

Weeks 4 to 5

This period is called the Early Stage of Pregnancy. The embryo grows and develops within the lining of our womb. It will divide into the 3 layers.

•  The Inner Layer – Baby lungs, stomach, gut, and bladder will start developing.
• The Middle Layer – Will become the muscles, bones, heart, and blood vessels.
• The Outer Layer – The Brain and Nervous System will develop like eyes, ears, and nose start forming.

The embryo is now attached to a tiny yolk sac, which will provide nourishment.

The embryo is now attached to a tiny yolk sac, which will provide nourishment.

Week 6

• Around weeks 6 to 7, your baby’s facial features will start forming. Baby will be 5mm from head to tail. The baby’s heart will start beating and rhythmically.
• Baby’s heart has begun to beat about 24 days after conception. Its arms and legs will start developing.

Weeks 7 to 8

• The embryo has grown to about 10mm long from head to bottom. The Shape of your womb has grown to the size of a lemon. The baby’s brain is growing rapidly and the head is also growing and forming.
• The legs are getting longer. The fetus is inside its amniotic sac and the placenta continues to develop. The fetus is getting its nourishment from the yolk sac.
• You will feel the drastic physical changes in your body.
• Like Bread Tenderness, Tried, Nausea, and Vomiting. Generally, it is noticed that after 14 weeks, earlier morning symptoms will become less effective.

Week 9 

At week 9, your baby is now about 1 inch long, the size of a medium green olive. His tiny muscles are starting to form. Some mothers feel the first kick of the baby.

The head has straightened out and is more fully developed.  And all of the baby’s essential organs, like the heart, brain, kidneys, liver, and lungs, have begun to develop.

You will start feeling very tired, and your weight will increase. Now, you will find it hard to fit in your old clothes.

• Frequent urination
• Fatigue
• Breast tenderness and changes
• Heartburn and indigestion
• Bloating and gas
• Constipation

Week 10

Congratulations, you’re now 3 months pregnant. your baby’s head has become more round. Now he has an elbow, Toes, and fingers, that become longer. The eyelids and external ears continue to develop. The umbilical cord is clearly visible.

Week 11

• Now your unborn baby is officially described as a fetus. This week your baby’s face is broad, the eyes widely separated, the eyelids fused, and the ears low set. Buds for the teeth start to appear.
• Red blood cells are beginning to form in your baby’s liver.
• Baby’s external genitalia will start developing.
• Your baby is now about 2 inches long from crown to rump.

Week 12

•  By now your baby might be about 2 1/2 inches.
• Twelve weeks into your pregnancy, or 10 weeks after conception, your baby is sprouting fingernails.
• The baby’s face is now fully developed. His or her intestines are in the abdomen.