help.. i had sex after birth

so when i made 2 weeks of postpartum of vaginal birth my blood flow was ending it was light brown & very light, my husband & i decided to have protected sex & during the process i was pain free it didn’t hurt at all so we continued & this is our 3rd time having sex & im currently 3 weeks but now my blood flow is heavy like my pad is full again is this okay?? or should i call my doctor??