Hello i recently had a herniated disc at l5/s1 and had surgery to remove the piece pinching my siactic nerve but my pain is worse than before surgery ?

There can be several: Reasons for this: a missed or retained disc fragment, wrong level surgery, post op nerve inflammation, post op scarring involving nerve, recurrent disc herniation, post op infection, there may have been conjoined nerve root present or the reason for your pain was not due to disc herniation. If you are smoker, success rate of spine surgery is significantly lower as well. Even more possibilities.

Postop pain: If the surgery was yesterday or within the last week, persistent pain can be seen. Typically the pain resolves quickly. But if you have persistent pain running down the leg and medication is not helping you may have a recurrent disk. Another imaging study may be helpful. More likely this is just residual nerve root irritation from compression followed by surgery.