I took plan B and missed my period. What should I do?

Dear Ask The Doctor: I had sex June 4, 2011. About 12 hours later, I took the Plan B one step pill. The following Tuesday, the 14 of June, I had unprotected sex again and I again took the Plan B one step pill. I experienced cramps, and a brown discharge mixed with blood after both times. It lasted for about a week and a half. It ended late June. July has passed and I haven't had a period. Could this be from the Plan B pill? How long can I expect my period to be messed up if it is? Should I be worried about pregnancy?

To be sure, do a home pregnancy test. Better do this in the morning because the amount of detectable hormones is at its highest during this time. I would presume when you took the plan B pill for the 2^nd time (after June 14), it was within 72 hours of unprotected intercourse. It is noteworthy that the plan B pill’s effectivity is ~90-95% when taken within 24 hours (day 1) and decreases to ~55-60% when taken within 72 hours (day 3). Your symptoms are common side effects of the plan B pill (spotting or bleeding, menstrual period comes too early or too late). Like I said, do a home pregnancy test; do it 1x every week until your period will appear. If you want to know right away, you can see your doctor and request for a blood pregnancy test. I do hope this helps and take care always.