Could i be pregnant even though i had my period?

i had my period this month, but it was different than normal, i normally start off light and it gets heavier over about 7-8 days, but this month it just started off heavy straight away and ended really quickly. my periods are always as regular as clockwork, and always the same. also i have been having stomach cramps and really sore swolen with backache, after my period, and i normally only get this a few days before my period. also my tummy is bloated. could i be pregnant?