I took plan b (42 hours after) about a week and a half ago. my nipples are really sore, and i have weird cramping/pink discharge. i am on lamotrigine.

Pregnancy unlikely: If your concern is pregnancy, the chances of conception after taking Plan B properly (within 72 hours of intercourse) are well under 1%. It's not impossible, so using a home pregnancy test to check may be reassuring. If the discharge does not develop into a normal period or persists, a check-up would be a good idea especially given recent unprotected sex. Lamotrigine not clearly relevant here.