What Causes Frequent Urination And Rashes On Body Post Unprotected Sex?

I had unprotected sex with a girl a week ago. I was partying and drinking a lot last week. I went to my doctor and got tested to everything.my test came out negative.my doctor told me I should come back in 6 weeks to get tested for hiv. In the last day I have been peeing a lot more than 8 times a day. I also notice rashes on my body.should I be worried?