I know that past sexual experiences don't matter in a relationship, but it still makes me feel bad.

Hi everyone, I'm 21 years old, and I'm about to start a relationship with a 24-year-old girl. We get along really well, our relationship is great, and she's already told me explicitly she wants a relationship with me. The thing is, even though I already knew her age and the experiences she'd surely had, these past few days, we were talking openly about sex, until she said something like..."On this subject, "There's very little I haven't already done." I'm not the type of guy who condemns a woman for the sexual relationships she's had. I've seen many people say that a woman loses value the more she has sex. But I don't agree with that at all. The problem is, even having this mindset and knowing that, in theory, I shouldn't even care about it, I felt bad. I keep thinking about it a lot. I get very upset. Whenever I have any sexual desire for her, I think, "Oh, but she must have already done that with another guy," and I get sad, imagining the scene. I know all of this is ridiculous. I know I shouldn't even care, but I still can't control this feeling. She's had sex with many people, and I've never been with anyone. Obviously, I don't feel any desire to condemn her for it. I don't think any less of her because she was very sexually active in the past, and I don't feel like ending the relationship because of that, because the love I feel for her is greater than all of that. But I'd like to know if anyone has any perspective or advice that might perhaps put my mind at ease.