can't tell if I'm over reacting or not!?

To give you the short story! Me and my boyfriend have been together for nearly 5 years. The first year he was talking to his ex .. Took us agessss but we finally got through it. But this last couple of weeks he's being strange again.. When I'm trying to talk He will zone out on his phone and and not because it's in his pocket or whatever. He will make the effort to make sure he has it.. E.g take it with him everywhere -toilet, shower, when it's on charge he will take it off to go downstairs for a drink then come back and put it back on.. I've looked through his phone once.. The time ifound out about his ex and never since (4years ago now!) and never want to - 
but on the other side.. He's talking about moving in, and baby names. But the thing is, moving in is 'if only' and 'imagine if' 
..we decided to come off of the pill (health reasons) but because he'd love to have children to and I'll most likely take 1-2 years of trying for us (if it ever happens naturally) the docs suggested we should sooner rather than later.. however again, we had sex last night.. And he stopped like what do we do now you're off the pill? I have one condom but it's to small. BJ instead? 
One minute he's talking about buying a house together after xmas and having children. The next he's worried about protection and more interested in putting the effort into his phone. 
It's been 5 years, a girl needs something. I would love a nest and a family. I'd love it much more than this unpredictable game thing I feel like we have at the moment :(