Can you be pregnant if your period is early and heavy?

If you did not engage in intercourse or some sort of activity that caused semen to come into contact with your genitalia, you are not pregnant. On the flip side, if you did engage in intercourse or sexual activity that caused your genitalia to come into contact with semen, you could be.

Let me restate that: you can be pregnant if you have sexual intercourse. Even if you menstruate after intercourse, it is still possible you are pregnant. The only certain way to determine whether you are pregnant or not is to have your doctor conduct a laboratory pregnancy test; even the OTC tests can be fooled.