If she is something special then i would go for her, really depends on how much you like her, but you can question her integrity and ask whether she is the type of girl you want. Since things are going well btw you 2, it may mean she isnt the trust worthy type, or it could on the other hand be a whole misunderstanding where you are getting the wrong signals maybe.
Heyyyyyyy, i guess i'm not the only one to have that shit happen. This girl I liked broke up wit her boyfriend a few weeks before. So I asked her out to a dinner date, to which she agreed to. The date went well, and I even asked for a second date to which she also agreed to...but then after that she stopped talking to me for about a week. Then I find out that she has a boyfriend. She bounces fast. I think you should just move on. No use holding onto a greased rope. Nothing will come out for either ends.