Ever since I got on the bc pill I have been experiencing vaginal burning that worsens after urination doctor can't find a cause could it be the pill?

Possibly. Different pills have different combinations of an estrogen and a progestin, or may be a progestin only pill. Each can have a slightly different side effect profile. I would discuss with you doctor and consider switching pills, or possibly stopping the pill for a couple of months and using another method of birth control to see if your symptoms improve. Good luck.