not baby related

Found out today my Grampa passed away last night. I'm sure when I was little I knew him but then things happened, my parents divorced, and we lived with our mom in another state basically cutting us off from that side of the family (not sure if my mom meant to or if she just meant to cut my dad out of our lives). Long story short I don't know my Grampa and I couldn't even tell my husband his first name. It's awful. I feel horrible because of that and because I don't know how to react to his passing. I did cry a bit but I'm not even sure what caused that. Was it the fact that I'm pregnant and it's sad news? Was it because I don't know how to react to it and that makes me feel like a horrible person? Or because over all that he's my Grampa, also the only one I've ever known, and it's sad to lose a family member? I also don't really know how to handle death. There's three including this one that I know of in our family. The first was a cousin with cancer, I was very young and didn't know her. At the time I knew it was something that made everybody sad but still too little to understand and comprehend what was going on. The second was my dads mom, still wasn't close to her but a lot closer than I was to my Grampa since I was still young and it wasn't long after my parents divorce so we were just moving and living in another state. While I was sad I didn't openly show emotion, which apparently opens you up to ridicule y an older sister who wasn't even related to the grandmother in the first place but whatever. She's always been a bitch to me why should a loss make her behave any differently. And now my Grampa. Still don't know how to act/react. I kind of feel like I don't even have a right to grieve because I didn't know him. I suppose I'll just have to see how the day goes. Thank you for letting me decompress.