When could i go back to my karate cl?

i dislocated my kneecap three weeks ago and i've done exactly what my orthopedist told me,i still walk with a limp and my knee hurts a little when i walk.before the accident i was in a karate cl,i totally digged it.i know i can't go back right now of course but i'm afraid that if i go back in a month or something and i try to throw a roundhouse kick my kneecap pops out again,so when should be a good time for me to return to my cl once my knee's properly healed?,plus i'm kinda traumatized for what happened to me,'cause i've read that when the kneecap slips out of its socket it keeps doing it within three months after the first time and that the joint is weakened permanently some please brief me on this.