How soon to return to work?

My son was born June 18th, and I also had my second c section. Although the healing process was wonderful then my first. I was able to do a lot when coming home. I been on leave since June and my new position at work starts on the 25th for pre-k pre planning. I've already have a sitter for my youngest son. I'm just nervous to have to leave him so early. Any suggestions ladies....