It is recommended to wait 6-8 weeks to allow your body to heal both vaginally or via the abdominal muscles of a C-section. Mothers who delivered vaginally may experience more pain and burning in the vagina during their first intercourse after delivering. Make sure to have lots of lubricant and make sure all stitches are healed prior to introducing the trauma of a penis. Spotting may occur after sex as well.
For c-section mothers, cramping in the abdomen or pain at the suture line may occur. Relaxin the hormone produced durng pregnancy to relax the hips to open the birthing canal may give you a false sense of flexibility. Muscle cramps and possible disjointed hips are possible but less common.