Parents not excited about pregnancy

When I told my dad about my pregnancy and gave him a cute frame I made with a sonogram picture inside, he just said, "That's nice," and handed it right back. My step-mother hasn't said a word about me being pregnant... no congratulations or anything. They were the same way when I got engaged... they had a could-care-less attitude. I'm a bit bummed out. My mother is deceased, so I'm kind of missing the family excitement around this. Anyone else in a similar situation? I'm trying not to let it get me down, as all that matters is that my DH and I are excited.