Is my girlfriend a ?

well when we first met, we would tell each other everything. after bout a 6 months of friendship we decided to get together and that's when other secrets came out,i found out she had only been with one other guy which is a plus nowadays.she also let me know she was "0nce" bi which i completely did not care about because i was already in love with her.she told me she would fantasize about and see them on objects in similar shape.after awhile of feeling weird but understanding she then told me she had a ual experience when she was younger with her friend,which is one of her best friends.It really made me feel wierd because i didnt ever think she had actually had a ual expierence with a girl but just found girls attractive .She moved down to where i lived to start a new life in a different state.she started working soon after and had few friends at work but had a real good friend she would text and talk to.i swear she told me this girl had a boyfriend,well whatever turns out we had a fight recently and she let me know the friend was a .she also has 3 best Friends that are gay men.i wonder why out of all the people in her work would she become attached and close with a .by the way this girl is not a butch but a regular attractive girl.Well turn out this girl has a really attractive girlfriend that also works there.they recently split up and the girlfriend quit her job and is now friends with mine on facebook.today she left a comment saying "i miss my gay girl" and another friend from work left "I heart you"WTF is this.My girlfriend tells me she is straight,but i wonder if she wants to be a and is scared because she knows her family and friends will not except it.i don't want to be with her and turn out she will become a lesbian years down the road and im left with nothing but hurt.i also dont want her to live a lie for a stupid reason and be hurt herself.we have been together for a year and a half now but this is all becoming new. am i thinking dumb or should i have concern