It is my third time having sex after losing my virginity and the following day ive been having trouble urinating - it hurts, i bleed lightly?

Bladder infection: This is almost certainly a bladder infection. Having sex significantly increases risk of these but urinating shortly after sex reduces the risk. 90% of UTI's are caused by E. coli and those respond well to D-mannose, which is found in cranberry juice, though if you can get a pure D-mannose powder that is best. If not improved with this in a couple days see a Dr. See https://tinyurl.com/h6wyn42