I don't know if this is helpful or not- but I was horrible at keeping contact with anyone while pregnant. I was so stressed and had so many things going on. I spent 4 or 5 months where every single week I'd say "Dammit, I meant to email my grandfather" before I actually did, I'd take weeks to call my mom. All my energy was focused on school (if she's working, it's probably focused on being able to keep up with her job in a similar way), prenatal appointments, and things that absolutely HAD to be done before the baby was born. I know it sucks, but, unfortunately, seeing the guy who knocked her up doesn't absolutely HAVE to happen, especially now that she has a boyfriend to support her.
I think it would be a good idea to raise these concerns with her, if you haven't. If she reassures you that you will be able to see your daughter and be a part of her life, it might be easier for you to back off until the birth.
Maybe a good compromise would be to ask her to let you know how each prenatal appointment goes- just so that you can know that everything's normal and all signs point to a healthy baby and ask if it would be possible to go to any other ultrasounds she gets (along with her boyfriend)? Ultrasounds are somewhat about parental bonding and most people don't get as many of them, so it might be easier for her to deal with than you trying to go to all prenatal appointments/whatever. I know for my partner, the baby didn't feel real until the ultrasound and a lot of non-birthing parents have said similar, so being able to go to the ultrasound would be good for that reason. She may not be comfortablew ith that, though, and you need to respect that if she's not.