Something Is wrong

Monday night I started with some cramps then Tuesday the whole day I was having cramps they were painful I went to urgent care they checked me out and Doctor said I have a UTI she prescribed me some antibiotic and I started taking them that same night but I have noticed my head hurts like really bad last night I couldn’t sleep at all i’ve been very nauseous I had to run-in three times to the restroom about to throw up and nothing comes out should I worry or is it just the affects of the antibiotics have been having a little bit of Crampy but not as much as before I feel like somethings wrong because the way my body is reacting or is it just the antibiotic worry here anybody have an idea