How likely is it could it be possible?

my period is suppose to be due in a week anyway i had unprotected with my boyfriend and he d in me so the next mornin i started bleeding feeling a little bit of period cramps and it didnt last very long it stopped all of a sudden and that has never happend before even though im not regular i usually go for about 6 days could i have possibly gotten pregnant?i have one child and would like another