Baby UTI

Has anyone ever had a little under a year old with a UTI? I'm really scared my 6 1/2 month old has one. :( He is drinking his milk pretty normally (for a teether) but isn't peeing very much at all. When he does have a pee diaper, it's more yellow than usual and it does kinda stink, although I've honestly never put my nose into his diaper until today lol. He's not running a fever or anything. A little bit of diarrhea here and there. He has a lot of blow-outs and has been swimming a few times this summer, which is why I'm even considering a UTI further. I feel like I'm just crazy and paranoid. :( can anyone help?