if you had a full on period and have not had unprotected sex afterwards, then it is unlikely you would be pregnant. however, if the "period' was very short and light spots, then pregnancy is a possibility becase the spotting was probably not a period.
Monee, if you are worried about pregnancy, go to the store and buy a home preg. test ASAP. take it 10-14 days following the sexual encounter in question. Or go to Planned Parenthood and ask for a pregnancy test; call 1.800.800.PLAN for an appointment.
In the future, know how to use safer sex methods, and please put them into practice and then you wouldn't have to freak out like this. Read this for more: http://www.scarleteen.com/sexuality/safer.html
And as Milke said, you are only allowed to reply to *YOUR OWN* questions in E&C. Please stay out of other people's threads.
Summertime, and the living's easy...