I haven't had an SO that had a sexual history quite that extensive. I would probably be concerned too. You didn't mention how far in the past all of this was, or her age (then and now), or how long you've been together, and things like that...I think that info would have an impact on how to...judge (I can't think of a better word atm ) her behavior.
I know I had a couple 'bad years' in college that I regretted when I matured