Feeling overwhelmed. Moments of regret

Hello I'm expecting my first baby in 12 weeks. I'm married it was planned, fine for money. The baby room is all ready I have been really excited getting carried away buying cute clothes. Now it's getting closer I'm starting to get a bit nervous. I have had moments where I have had doubts and think maybe I should of waited another year. Has anyone else had this? I feel aweful for thinking these things.