Sorry about losing the baby
It must be hard enough to lose a baby, but it sounds like it is made worse by your parent's not being sensitive to this. Many people don't know how to handle grief or how to act in these situations, so just avoid the person-could this be whats going on with your parents? Did you guys ever talk about the loss? I think letting your parents know that you are hurt by their pulling away from you will help, especially because they may just be oblivious as to what is going on. They can be excited about the grandbaby, and still have time and energy for you.
Me and my sister are due within 2 week of each other with the first grandbabies (she's having a boy and me a girl) and I can't imagine what would have happened if one of us had a mc or something. I have to admit, that if I hadn't gotten PG at the same time as her, I would have been a little jealous because I am the oldest and always thought *I* would have the first grandbaby.
Sounds like what you are feeling is normal-good luck!