Hi Occurance of postcoital bleeding is not normal. It can occur due to several reasons. Infection on the cervix, cervical erosion. cervical polyp, precancer lesions and cancer cervix can all cause postcoital bleeding. It is extremely important that you visit your gynecologist and have the cervix examined and treated accordingly. What type of precancerous cells were found in your pap smear before. Was it low grade or high grade? In view of this history you must do colposcopy and biopsy to evaluate for precancerous lesions even if the cervix looks normal. Based on the biopsy results you can take treatment. I hope I have answered to your satisfaction. If you have any further queries do contact me through healthcare magic