Confused could I be pregnant from last month?

Hi ladies I got my BFP last week assuming that I got pregnant from this month, but here is the thing I had my period for April and it started on the 29 of March and ended on the 2nd of April I had sex a couple of time in April and then my period started on cycle day 25 and lasted just for 4 days my period has never came that early and has never been 4days always 27-29 and 5 days. So I took it as a period So for May I didn't get my period for could I be pregannt from last month or no ?