I've urinated 5 times today and had no fluids, anything to be a worried about?

How much last night?: Your body takes a little time to process liquid intake, so if you drank a lot (of anything) last night, you could just be catching up. Probably nothing to worry about. If it hurts or stings when you go, though, and you are only producing little bits each time (even though it feels like a lot), you might have an infection and should probably see someone for a urinalysis.

It depends on cause: Frequent urination can be due to infection in the urine(Bladder). In that case(cystitis) there is likely to be burning, stinging pain when you pass urine. There is also sense of urgency but not much urine comes out. If you have no such symptoms, then you should watch for another 1-2 days to see if this problem persists in which case, go see a doctor for check up. Cystitis requires antibiotics .