UTI symptoms TMI

I had some burning while peeing Sunday and painful pressure when I had to pee. I've never a UTI or anything so I wasn't sure if it could have been one. My mom told me it probably was. The only thing is Sunday I didn't stay hydrated. I woke up at 2pm and when I got up we went straight out to eat where I had soda. Then we went out shopping and I didn't drink anything while shopping. So I am on the fence if I have a UTI or we're my symptoms caused by dehydration. Yesterday I drank a lot of water and was fine. I peed this morning and had small amount of burning, medium colored pee, and painful pressure. I called my doctor and made an appointment to get tested tomorrow since I heard UTIs are bad for you while pregnant. I'm nervous if I don't actually have one my doctor will be mad at me. I have an appointment on the 14th and worry maybe I should have waited until then.