I was in a wreck a month ago. 3in facial laseration its healing but around it is numb and its leaking yellow fluid. what could cause this?

Infection?: It is quite possible that your laceration is infected, as the yellow fluid you describe could be pus. The only way to tell is to have it examined by your doctor. Make an appointment ASAP. Best wishes.

Complications: Since the laceration was deep enough to require suturing, most likely it was deep enough to cut some of the tiny nerves that provide sensation to the injured area. These tiny nerves eventually heal in most cases but can take several months. The leaking of fluid concerns me more and might indicate that part of the laceration isn't healing properly. Get it checked out.