Feeling ambivalent

Telebell

My husband and I have been together for about 2.5 years, married for just under one.  Both 30 y.o.  He really wants kids, and I also want a family, but only rarely have I felt deep down that I *want* kids.  I've never felt that biological urge or longing for a baby.  

We'd initially thought to start trying for a baby this coming fall around our 1 yr anniversary, but sort of on a whim I decided in July that I was ready.  And I got pregnant on the first try after years on birth control.  

 I've been more emotional than normal, but - I still don't feel as excited as I perhaps should.  What's making it worse is that we just went on a vacation including our lovely 3 y.o. niece, and I didn't feel particularly warm towards her.  Spending time alone with her was pleasant, but sort of boring.  I could think of about 15 other things I'd rather do than watch her.   I literally cannot think of anything to say when I'm with her alone.  

 I feel terrible, in a "what are we doing?" kind of way.  My H and I have such a nice life together right now, and I'm aware of how much you give up (traveling on a whim, sleeping in, having your time to yourself)  when you start a family.  My H is so nice about it, keeps telling me that he'll do so much of the child rearing, etc.  That I can go out by myself whenever I need and he'll be home with the baby, etc, etc...

 I'm hoping this is partly pregnancy hormones, but I'm starting to feel like we made a big mistake.  Please tell me anyone else sometimes feels this way.