3 Increase in breast size
Your breasts begin to grow in the first trimester and continue to get larger through the second trimester, in preparation for milk production. The tenderness of the breasts decreases in the second trimester, but size keeps increasing due to the proliferation of milk-producing breast glands.
4 A dark line on the belly
A dark, pigmented line can appear in the center of the belly. It is known as linea nigra. This pigmentation occurs due to the hormonal changes associated with pregnancy. It extends to your pubic area.