6-8 weeks. Factors that may affect your return to sexual activity include: vaginal delivery vs c-section, easy vaginal delivery vs difficult delivery with large episiotomy, breast feeding (can actually delay the recovery of the vagina due to low estrogen), how much help and support you have. I think 4-6 weeks is the minimal time to delay sexual relations. 3-4 month delay may indicated other problems.
6 weeks. Resumption of sexual activities after pregnancy is typically advised after 6 weeks of recovery time, whether its a vaginal or cesarean delivery. If you had an episiotomy or vaginal laceration, it may extend your convalescence period. Whenever you do resume sexual activities, it is best to take things slowly and listen to your body, using lubricants and foreplay liberally to ease any discomfort.