Advice needed

So I've been talking to this girl for about 2-3 months. Shes a state away so we haven't met yet. We'll be hanging out for the first time this weekend. Anyway, she's been telling me about this guy she used to sleep with. (we're both bi) Which is fine with me since they ended it a couple months before we even met. Plus he's got a girlfriend. The thing is, they work together, which didnt bother me until today when they got out on the same shift and she ends up "accidentally" sending me a snap chat of them blowing a kiss to each other.😒 I think what makes it worse is that I really dont like him.

On top of it all, there this girl she was in love with before even him that she still talks to everyday and is friends with that's suddenly come back into her life.

I dont know how to feel. I'm not used to being jealous. If that's even what I'm feeling? Like on the one hand, we aren't together so w/e but on the other it's like, isnt that what we're working on? Am I dragging this out of porportion? Or should I be listening to these red flags? She doesnt see anything wrong with it which makes me wonder if that's a red flag in itself or maybe I am more invested in her than I should be? I dont want to be one of those psyco girlfriends whose jealous of everything and everyone but I cant get this feeling out of my stomach. Maybe it's my gut trying to tell me something🤷‍♀️

What do you think guys?

Should I listen to my gut or take a chill pill?