Basically on Monday I had unprotected sex. Five days later I started quite heavily bleeding, this only lasted 2 days. This was also 2 weeks before my period is actually due. Does this sound like an early period or could it be something serious? I have had sex three times before this so it isn't because it's my "first time".

I also haven't had any stomach cramps or tender breasts like I would usually get whilst on my period.