I Had Unprotected Sex On The Last Day Of My

i had unprotected sex on the last day of my period may 9th and he came inside me. i took plan b about an hour after and got light bleeding the same month and then one day of really heavy blood. my next period in june was exactly one week late but i got it usual amount and for a full 7 days...is there any possible way i could still be pregnant because i have read that pregnant women can still get their periods?