I don't feel like a mom...

I'm 23 weeks. I have a few friends that are around the same gestation as I am. I feel like they're all sooo excited and attached to their babies already. But I am having a hard time feeling like I am actually a mom and getting attach to this baby. I'm a first time mom, I dont know if its normal, or if it just hasn't hit me yet that I'm going to be a mom. Anyone else feel like this? Is it normal?