I think we all have doubts.
I'm 24, married and we had decided we wanted a baby but that doesn't stop me having doubts about whether I'll be a good mum or if this is the right time in my/our lives and if we can afford it.
I just keep telling myself that it's natural to worry about it, it's a big thing.
And I think underneath all the doubts I know it'll be ok, I figure if it's meant to be it will be.