Hi there
I can really understand your feelings, as I lost my mum when I was about 12 weeks pregnant (after a near miscarriage at 8 weeks) and went through the whole pregnancy feeling like I did not really want to have the baby anymore. I did not exactly feel like she should have died, but more felt apathy towards everything to do with the pregnancy. Other people were buying baby items and clothes and whatnot, and I kept things to an utter minimum, just getting a few essentials when I was about 38 weeks. It was a bit like I was in denial about having the baby at all.
After the baby was born, I was also expecting some kind of crash of grief, and I will be honest there were times during the 3am feed when I was tired and feeling low, that I cried for mum and it felt very unfair, but at no point did I have a really big crash. I also still feel like I am waiting to have time to grieve properly (DD is now almost 3) and still waiting for it to sink in properly.
I did bond with DD when she was born, although not immediately. I found my in built need to keep her at least safe, warm and fed kicked in, even if I did not have the massive rush of love and pride I feel now every time I see her when she wakes in the morning and comes trotting into my room to see me - that took time, maybe 6 to 10 weeks, to really feel like she was something extra special in my life.
I think it is positive you are not trying to hide or bury your feelings, have you considered talking to your GP about it, it is possible to have pre-natal depression, and there might be something they can suggest to help you get through it. I cannot promise it will all be fine when the baby gets here, but I can tell you it was for me.