Is the light bleeding a UTI symptom or the start of my period?

Hello. A tiny amount of blood when you pee, is definitely something that will happen when you have a UTI. It usually will only happen when you pee though. Period blood is more likely to occur at other times, not just when you pee. Periods usually don't start and stop like that, so my guess is that the little bit of blood you're seeing is from your UTI. Take care :-)