Should I go or follow through with my plans?

I've been planning a bus trip for months to go upstate. I have 50 paid guests going on the trip. We recently found out that my husband's grandmother ped away and the funeral is the same day as my bus trip. My problem is that I want to be there for him but I can't cancel the trip one week before the date. The bus company does not give refunds this close to the trip and it is a full bus. One of my relatives was going to drive 9 hours to come on the trip to help me out as my istant. She said she would host the trip without me but she doesn't know anything at all about the area and I can tell she is uncomfortable doing so but just willing to help. I am pregnant with my first and been going through quite a bit of stress lately. This situation is stressful because I feel I have a duty to my husband but also to the 50 people going on the trip and my family going to help out. My husband told me to stay and do the trip since it was planned. What would you do (serious replies only pls)?