When to get angry at inlaws?

I am 27 weeks pregnant and my mom is prepared to be here for the birth of the baby, and is planning to stay with us to help out. We have moved across country since the birth of our first child, so I figured that every one would be wanting to come out to see the new baby. I asked my husband when is his mom and dad/stepmom were planning on coming out, and he said he did not know. Now it seems as though they are waiting til we come home in the summer. Should I be angry? I feel like it is a one way street when it should be a two. What kind of grandparent does not come to see their new grandchild, and what kind of parent is not there to support their son? Is it just hormones making me over react? They travel to see friends and nieces throughout the US but yet they cannot be here for a special day. I just do not get it. What would you think? I am just thankful I have a helpful mom who cares, it is just sad for my husband!