Advice??,

So my baby daddy and boyfriend has another kid who no one knows if its his. Now the girl is messaging his mom sending pictures saying this is your grand daughter. This girl told his mom to kidnap him so he could be apart of his child's life. Would she just say that out of the blue if her and my boyfriend haven't been talking?, I want Jim to be apart of that kids life but I feel like he is doing it secretley behind my back and that's not OK. We use to have the type of relationship to where we could get on each others phone anytime no passwords now if I get his phone he yanks it from me. If I ask for the password he won't tell me. I'm 18 weeks pregnant with his son and I'm only 18 myself. He's 21. I don't know if I am tripping, if I should just wait around and see or if I should just go right ahead and say fuck you and leave. ??? Anybody know what to do. Tell me if I'm being a hormonal dumb bitch or I actually have a reason to be this way.