Hi, I had unprotected sex about four nights ago, and my period started normally, when it was due, and yesterday it started to be irregular. It stopped, the in the middle of the day I started bleeding again, and a few hours later stopped again. Then that night I had bad cramps . Today, the same thing happened. Yet, I haven t had cramps yet. Let me remind you, the man did not ejaculate in me, but he did pre-ejaculate . Should I be worried that I m pregnant?