Can't bond with my baby.

So, I just feel like I want to bond so badly with this baby I'm carrying inside my freaking BODY! I want to so bad, i really do, but I feel like the lack of excitement from my mom just makes it so hard to actually bond with my baby. She's my best friend and I'm hers, but when I got pregnant, she was understandably upset(I'm 17 years old) but when this happened with my sister, she was just so excited and wanted the baby here already. She's told me a few times that she doesn't love this baby yet and she's not at all excited, so I feel like that's keeping me from being excited. I have her support and support from my whole family and my boyfriend and his whole family, but it's just hard when I know my mom is uncomfortable.