Am I completely crazy or is this normal?

Well I congratulate you on the outstanding relationship! What? 3, 4 years? That's amazing! I honestly think that if you're mentally, emotionally, physically, and if you can afford to have a child and if you have a steady job THEN you should have kids. A couple should have stable jobs, stable income, stable housing, etc. To make sure that the child's life is as smooth as possible seeing as you're young. If you and your boyfriend are really that serious, then I say go for it! Hope that helped :)