Had unprotected sex on first day of period. Took plan b 5 hrs later. No side effects but did notice huge difference in period. (not as heavy as it usually is, darker in color, and NO cramps witch is very unusual for myself) I was wondering if I should take a 2nd dose of plan b to be on the safe side, afterall pre ejaculation is always a factor. How soon should take a pregnancy test? Hasnt even been 1 week since.