If you decide to make adjustments yourself, start small!
I also advise getting fit at your LBS. Tilting the saddle too far up it the most painful thing I have ever done.
I've also had other factors. I switched to a Brooks leather saddle. When my core gets lazy, I slide on the saddle. It keeps me honest, and reminds me to use my whole body to stay in position. I learned from spinning class that my core needed more work.
You also might want to take a look at the saddle itself.
"Well-behaved women seldom make history." --Laurel Thatcher Ulrich
'09 Trek WSD 2.1 with a Brooks B-68 saddle
'11 Trek WSD Madone 5.2 with Brooks B-17