Week 5 of First Trimester
Discover what happens during week 5 of first trimester. Baby development, body changes, symptoms, and a weekly checklist.
What's Happening This Week
Welcome to the week of change - massive, enchanting, riveting change! The plus sign on the test is a symbol of transition into a bright, invigorating journey for both you and mini-you(s)! Ensure you have double-checked the result by taking another test. Go ahead and make it official by visiting the doctor.
First Trimester is a time of rapid change — for both you and your baby. Every pregnancy is unique, and the information below will help you understand what's happening and how to prepare for the weeks ahead.
Your Body
The gestational sac is now visible and growing inside the uterus, providing a protected space for development. Hormones like hCG and progesterone are rising quickly to support the pregnancy and prevent the body from rejecting it. Even if nothing feels obvious yet, your body has already committed to sustaining this pregnancy.
Your Baby
Your baby is about the size of a sesame seed (around 1–2 mm). Right now, three essential layers are forming. These will become the brain, spinal cord, heart, and all major organs. The heart hasn’t started beating yet—but the structures that make it possible are already in place.
Your Week 5 Checklist
Each week brings new things to prepare for. Here's what expecting parents during week 5 typically track in the BabySteps Companion app. Items are sorted by priority so you can focus on what matters most.
