Week 4
A pregnancy test may turn positive late this week as implantation finishes. The sac is tiny; many people feel nothing yet, and that is ordinary.
Length and weight
Length0.1 cm
Weight0 g
Early weeks are crown to rump; later weeks are head to heel. The bar is not a ruler. It is a rough comparison with the average at week 40.
Approximate
Ask your midwife or doctor before you change medicine, herbs, or a birth plan.
Related
The first trimester
Weeks are counted from the last period, and the early body is allowed to feel strange without owing anyone a glow.
Sizes and dates are averages. Feeding and sleep notes follow widely published public-health guidance, including World Health Organization infant-feeding advice and back-to-sleep recommendations. They are not a protocol for your hospital.