First Trimester
Week 4
Reviewed by Dr. Humaira Latif, OB-GYN & Ultrasound Specialist
Welcome to week 4 of your pregnancy. Here’s a gentle look at what to expect at 4 weeks pregnant — baby’s size, changes in your body, common 4 weeks pregnant symptoms and a caring tip from Dr. Humaira.
Baby's size
About the size of a poppy seed.
What's happening
The embryo is implanting fully. The placenta is beginning to form, and hCG hormone is now being produced — this is what a pregnancy test detects.
Your body
A home pregnancy test may turn positive around this week.
Common symptoms
- Missed period
- Sore breasts
- Fatigue
- Mild nausea beginning
When to call your doctor
- Heavy bleeding
- Severe pain, especially one-sided
Dr. Humaira's tip
A faint line on a home test is still a positive. Book a confirmatory beta-hCG blood test and a first prenatal visit.
Educational only — not a substitute for in-person medical advice. Always follow your own doctor's guidance.