The day I fooled around (didn't have penetrative sex) was a few days short of a month ago. A little more than two weeks after the day we "fooled around" I got my period (actually it came a few days earlier than my monthly normal). It was a normal heaviness flow but it only lasted three days. My periods are usually around 4-5 days. Could it be possible that it was implantation bleeding? Is it possible to have your period while pregnant?