I took the plan B pill about 5 hours after having sex and the second one 12 hours after as instructed. I got my period a week early and it lasted about 2 1/2 weeks. I'm not exactly sure when to expect my next period. Should I calculate it from when I started my last period or should I calculated it from when I should have started my period or should I start to get worried about pregnancy? If I calculated it from when I did start I think I'm about a week late. If anyone has any help I'd greatly appreciate it.

I took the plan B pill about 5 hours after having sex and the second one 12 hours after as instructed. I got my period a week early and it lasted about 2 1/2 weeks. I'm not exactly sure when to expect my next period. Should I calculate it from when I started my last period or should I calculated it from when I should have started my period or should I start to get worried about pregnancy? If I calculated it from when I did start I think I'm about a week late. If anyone has any help I'd greatly appreciate it.
Dear kpeciulis--

I believe that any big hormonal invasiveness on your body will cause your menstrual cycle to be off for a while. There can be no for sure way to measure when your period is going to restart, however, if you are this worried, I would suggest buying a pregnancy test. If after 30 days, your body is not yet back to normal, or there is any further unexpected bleeding, I would consult your physician.