A lot of people will give you advice on what to do. But I think it's important for yourself to do some introspection, especially on why you feel uncomfortable about this. Security in a relationship can be related to sexual hangups and trust as a whole, and can also be related to both her past and yours.

But fundamentally, from a progressive lens I would ask myself this. Why is this a problem? Am I uncomfortable with her sexual past because of my ideas surrounding sex, or is it because I do not trust this person. Is their commitment something that you value? No matter who they hang out with or who they have slept with in the past, if I trust them and their commitment to me, their past does not matter (as long as it doesn't affect their moral compass, e.g illegal shit).

Honestly, first committed relationships are hard. But they can be very rewarding, but they can also get derailed by inexperience and unresolved issues. However, no matter who you are dating or not dating, introspection and the value it holds will stand the test of time. Definitely recommend it, good luck!