What Causes Normal Menstruation While Planning To Get Pregnant?

Me and my partner are eager to know if i am pregnant? Its only been 3days since we had un-protected sex. My period is normally right at the beginning of the month, usually around the 5th but last month my period came on the 11th of october. This month(november) we had un-protected sex on the 5th and 6th to try and conceive but today which is day 7th, i've started to bleed? Now i'm a bit confused and worried.