My husband's family wants to come up this weekend but I've been so moody and in so much pain lately…

My husband's family wants to come up this weekend but I've been so moody and in so much pain lately I'm really not up for company. I've been crying from the pain literally every day, and the thought of having to entertain people/spend money is not appealing to me. Plus it's really our last couple of weekends just the two of us, I want alone time. Is that selfish to tell them no?