3 weeks ago i took the plan b pill. a week later i was spotting, my period is now late. and i had unprotected sex 2 nights ago. what should i do?

Check Pregnancy test: The plan B alters the hormonal environment so you do not get pregnant, but in so doing, can certainly alter the normal rhythm/time of your cycle as well. Plan B should not be used as Birth control, so you really need to see a GYN and get on Birth control and as well should be using condoms. In the mean time, check a pregnancy test, then see the GYN. Best wishes.