How can I be sure he'll be a good father?

My husband is a wonderful, supportive man. We have been together for 3 years and we have always intended to have children together. Unfortunately, he is a bit of an absentminded professor: brilliant but distracted. He needs several reminders to do basic chores, even those he does every day. When I ask if we're out of milk, he'll say he doesn't know, even if he's holding the empty milk jug.

Recently I had to go to the emergency room, and while he was wonderfully supportive, he was not that great at helping me when we got home. Last night I asked him to get milk on his way home, which he did - and then he didn't put it in the fridge, but left it on the counter overnight. He promised to throw it away before he left for work, but I just came home and found it still on the counter.

I've told him that this kind of inattention to detail makes me worry that he won't be able to care for a baby, and he promises that he'll do better "when it matters." It mattered to me when I was ill, and it matters that we have to buy milk again. I'm not nitpicking about the chores - I don't care how he loads the dishwasher, just that I have clean pots when I'm cooking dinner. Can I trust him to figure things out, or will I always be looking over his shoulder to be sure the pots get cleaned and the children get fed? Should I just expect to take care of everything from now on?