Telling your in laws you are pregnant

My husband of 4 years and I told his parents that I was pregnant. Their backs were to us because they were packing things. Once we told them they continued to pack things and didn't stop and turn around to congratulate. My father in law said, now you are really family. Not in a nasty way, however it hurt. 
I'm so hurt. I wish they could've been happier. 
How your in laws take it? I hope good!