Period the day after I lost my virginity

On October 6th I lost my virginity to my boyfriend of 6 months. It didn't last long since it hurt a bit. we didn't use protection but he didn't ejaculate. The next day I got my period, even though I wasn't expecting my period for another 2 weeks, and it was heavy and I had bad cramps. Today it started off heavy but now its getting lighter. And I had very mild cramps. Is it normal for this to happen? Can I be pregnant?