CrazyC- I have a little tool I carry with me for small adjustments on my bike. It has various sizes of allen wrenches on it which are great.

If you have this tool (you can get it at your LBS)you can adjust the seat height yourself. Have someone at the LBS show you. I will often play with my seat height when I'm out on a ride. You'll discover right away if that's where the problem is. Just be sure you get the adjustment tight! You can also tape where the seat was so you have a benchmark.

The other suggestions about positioning your seat will also help.

Another area for adjustment is your handlebars/stem. I'd go to the LBS for that one. It's amazing what a small adjustment will do for you, trust me!