UTI or just potty training stress

Hi ladies. We are potty training our son this week both at nursery and at home. We are starting to wonder if our son has a UTI or is it just potty training stress? He is waking out of his sleep (has a pull up on) and is either bouncing up and down or rocking back-and-forth as if he’s in pain….well I know he’s in pain because he’s crying as well. Just acting a bit weird which is very out of character for him, he’s being quite clingy too, he isn’t normally a clingy child. I thought he had a sore bum but I think he might have a UTI, has anyone else seen similar symptoms? I’m thinking of taking him to the OOH doctor today. We are making some progress with the potty training so when he’s crying on the potty, I thought he was just upset about the new sensation of going in the potty. I’m so clueless about potty training 😂Thanks