What you're drinking and when you're drinking it can also affect when you pee. Why not keep a little diary of what you're drinking and when you're going for a few days to see if you can catch patterns. Alcohol and caffeine (don't forget sodas with caffeine) can have you going more and drinking anything after about 8:00. Too, are you going to bed and getting up your usual times? If you go to bed earlier and/or sleep later you could just perceive yourself as going extra times but you might have gone then if you were awake?

For me, I pee in the middle of the night because it's "safer" and no one else knows, etc. I had issues as a child and so am not as comfortable going at other times, don't do well when the doctor orders urine tests as I have trouble peeing on demand :-)

If you have a medical problem I think like Tryin says you're going to have to go for a simple test or two anyway. If you wait, things can get worse and cost more.