Helping husband mourn

It hasn't hit him yet, and I'm 6 months pregnant so I'm trying to keep my stress down and prepare myself for when he's ready. My husbands grandma passed away last night. A few weeks ago she went to emerge because of constant pains and fatigue, they ran tests and found out it was cancer. Within weeks it escalated and she got worse and worse through the days. Yesterday they brought her to a hospice, and she passed just after 1 AM.

My husband and his grandma were extremely close, she basically raised him, supported him through school and his job, and they talked about everything together. He's cried a little bit, but has admitted that it hasn't quite hit that she's actually gone.

I've seen him cry a max of like 4 times in the 3 years we have been together, and they were over small things, 2 of which were happy things, so I'm trying to prepare myself for what will be coming. Any tips?

We just lost my grandma last year to cancer as well, she stayed at the same hospice as his grandma did, but was there much much longer than his grandma was, but my husband didnt get to know my grandma as much as I got to know his. His grandma and I were quite close as well but it's already hit me