Had unprotected sex 7 days ago. took plan b 6and a half hours later. for 2days now having heavy bleeding and bleeding black/brown clumps. pregnant?

Probably not: Plan B involves a fairly large dose of hormone in order to avoid pregnancy. The quick withdrawal of those hormones can lead to shedding of the uterine lining and unusual bleeding. A pregnancy test can be done ten days after intercourse to allay your fears. If negative, probably no pregnancy from this episode.

Not likely: It is unlikely that you are pregnant, but run a pregnancy test to be certain.