Just wanting to rant/purge

Nee
So I'm a big believer in the  marage and family and white picket fence dream
I haven't been with my partner long. Just 3 months but  He has an 18month old son to another lady and right now I'm almost a week late on my period. And I would never dream of giving up a baby! I know I could just be late my TOM is late all the time. But a girl can dream. But maybe he isn't ready for another one. 
Anyhow  he was looking at rings just last week when we went to get a CT scan done on him. I had to walk away because I just can't think of moving that quickly yet. I love him with all my heart and if he asked me I would say yes in a heart beat. But I meant how fast is toooooo fast right?
I have had to move out of town for the time being due to work and I kind of want to have the whole commitment thing with him made overly official. 
Like engaged type official but I really don't know how to talk about our future together as a couple because of all these other things that are going on. 
If you ladies could give me some advice/ guidance on how to talk to him about that kind of stuff before it's too late and things happen before we BOTH are ready.