Now, I know this is a cause for concern. When I pressed the issue, she said if I had asked a while ago, it would not have been a problem. I just don't see why it would be now at all, or at any point, in the relationship.
Basically, I was wondering what I could say in order to get her to do it since I can't physically MAKE her. I'm not really suspicious, but by her declining to do so, it makes me suspicious.
Edit: to say that I am not really familiar with how any of this works at ALL and this is my first sexual relationship.