If this continues, I recommend seeing your family doctor to make sure this is nothing serious. There is not enough information given that will let us know exactly what is going on.
Drink real cranberry juice and lots of water, could be a bladder infection (quite common from a hot tub), take Tylenol if it gets painful not ibuprofen.
UTIs can be caused by bacteria, viruses, fungi, and even parasites. Avoid sitting around in wet bathing suits and hot tubs - these breed germs.