Could be a bladder infection, or could be something else that needs to be looked at?

If you have had UTIs before... I don't know, I have never had a bladder infection but I imagine it would be much similar to a UTI, in which case I drink litres of cranberry juice for a couple of weeks, that fixes it. (it usually clears up within a day or so, I continue to make sure it stays gone)

If you have a temp, or it lasts more than a couple of days (as Rivlas said) or seems like it could be something else, couldn't hurt to go to the docs to get it checked