if it doesn't hurt than you may just have a weak bladder or maybe you drink loads, I need the toilet all the time- its really annoying, in preperation for long car journeys I don't drink anything for 2 days
Is this something that's only started recently? If so, I've had something similar a number of times and it just went away by itself. The first time I had it, I went to a GP and she couldn't find anything wrong with me (but I'd still recommend going to see your GP - what you have might be different to what I had).
Also, have you been eating/drinking a lot of sugary things? During the exam period I did just that (I eat when I'm stressed) and I found that that it made me need to pee a lot for some reason. I think it has something to do with excess glucose being ejected from the body via urine, but I'm not sure.