My husband proposed to me after we had been together 3 months (we got together 14th July and he proposed on 19th October). He was very serious, yes, so don't assume your boyfriend isn't serious. Sometimes you just have a feeling that it's the right thing to do. If he feels as though you're the right person for him, what benefit is hanging around waiting? After all, he's 30. Maybe he wants to start a family with you and so on.