Light Period

Is light period really caused by pregnancy or is there any other factors that could pertain to it? What does a light period look like? I think i’m having a light period because of it being pink but i think it’s also because i kept drinking water and have a uti 🥺 Whenever I pee, it’s dark red and has those little chunks of blood but when I check my pads, it’s pink and almost no period. It’s my first time experiencing this.. pls help!!