What Causes Discomfort While Urinating After A Pap Smear?

I had a pap smear today, and about 2-3 hours after began having discomfort when urinating, which has become extremely painful, burning, and cannot seem to finish. I happen to have sulfamethoxazole-tmp on hand. I haven't had a bladder infection in 20 years, but this feels like one, and I happened to have had a scare last year that resolved by itself. I'm desperate for relief.