Week 3 · First trimester
Week 3, gently.
Your baby is the size of
a poppy seed
- 0.1 cm long
Your baby right now is a hollow ball of cells smaller than the period at the end of this sentence.
“A tiny raft of cells, finding its place.”
What’s happening inside
Conception happens, and the fertilized egg travels down the fallopian tube, dividing as it goes. By the end of the week, a ball of about 100 cells called a blastocyst is nestling into the uterine lining.
How you might feel
Nothing outward has changed. Inside, implantation is happening — some people notice very light spotting (not a period) or a twinge of cramping.
