We wish you and your husband the best of luck.
My recommendation is that, while he's inpatient, you spend as much time as you can with him in the treatment center. In my experience, transplant patients can be awake, asleep, loopy from medicine, confused, anxious, lonely, or feeling OK at all different unpredictable times of day. If you or another family member can be there to be his advocate, hear anything the doctors and nurses tell you, and keep him as comfortable as possible, it'll be that much easier for him.
Please let us know how it goes.
Founder of Marrowforums and caregiver for my wife