Re-herniated L5S1 disc after 2 microdiscectomies?

Hi all, I have a disc herniation on L5S1, it's going straight into the nerve route which causes sciatic pain down my left leg. I've had 2 surgerys on it, both microdiscectomies, although each have helped (before the first one which included some bone removal I could hardly walk and was taking morphine), it's still not great. Im 2 weeks in after the 2nd surgery and getting quite a lot of pain in my bum cheek and stabby type pains down the leg I'm worried it's herniated for a third time I'm still resting a lot, not driving etc and really don't want more surgery when it doesn't appear to be working, does anyone have any suggestions, similar experiences or advice they can give me? I'm thinking I may have to live with this or could be worrying for no reason although from past experience my body doesn't seem to heal well .
I was thinking maybe to start building strong core muscles with swimming and Pilates rather than looking to surgery again to try to get rid of the pain permenantly, but could do with some advice. Totally fed up
I'm 27 and currently on leave from work
1st surgery -23rd march 2012; 2nd surgery - 1st may 2012