Period & had unprotected sex during the last day and following 3 days. i started having extremely sensitive nipples 2d after sex. no bc 2 mos. ideas?

Pregnancy: It seems a little bit early for you to be having pregnancy related changes in your breasts. That being said, you could have gotten pregnant earlier or you are at risk of pregnancy and really should consider getting tested or being observant of your next period. Look for any redness or any excoriations of your nipples because that could be either pain related to minor trauma or a yeast infection.