Do it.
I guess I am in a similar situation in that I don't need to work and DH would be fine with me staying home if I liked - however he also was very supportive of whatever I wanted to do.
When I first went back childcare pretty much ate all of my salary, but that first paycheck after being off for a few years was just gold. 
I love getting paid, but that is only one of the benefits of working IME.
Also being back a couple of years now, childcare costs are lower and I have moved 'up' so my salary is higher.
I think it is good for the kids as well, they see their Dad having to pull his weight around the house, they know that my needs and work is important, they learn about compromise and while they are very very very high up in our priorities sometimes they miss things because we both work.
All of these are good life lessons IMO.
Too many stories on here and in RL of SAHMs being left high and dry.
I trust DH completely, but I need to be able to stand on my own two feet. Husbands don't have to leave to be gone, they can die, they can be incapacitated - shit happens.