When will my bf pop the question

My boyfriend and I have been dating for over a year and a half, we live together, and were friends for 6 months before we started dating. One of the main reasons we got together is because we have a lot of the same life goals, 3 kids, nice chunk of land in Oregon ect. For the last 6 months he always talks about what life is going to be like when we're married. He'll say, "when we're married, and moving to oregon we should do (insert something adorable here)" He thinks of what our kids will look like, how we will be together when we're old things like that. I feel the same way and we talk like this all the time. So Im at a loss to why he hasn't asked me anything? Is there a way to help him along or should I just cool it.