If the piercing becomes red between the entry and exit holes then it is a sign that the piercing is being rejected. If it has a lump of discharge then antibiotic ointment should be used to clear up the infection. Medical treatment must be sought at the first sign of infection since if it is left untreated an infection will cause the rejection of the jewellery, and may lead to greater health risks.
Pubic piercings have a bad reputation for migrating out. There are a variety of relevant factors. One is the "pinchability factor" of the tissue. If the tissue doesnt pinch up well, and fits quite tightly to the body this will make healing (and the piercing process) more difficult. The ability to allow it to heal with a minimum of trauma is important, and starting deep enough, with sizable jewellery is vital. Most piercers suggest a 12 or 10 gauge, 7/8" ring to start, which allows for placing a good amount of tissue in the piercing. It is normal for them to lose some tissue as they heal.