My husband has no sex drive! I want a baby!

So my husband normally can have sex maybe 3x a week less a lot of times. He has a very hard time getting off too.. he says it's hard for him. So I am wondering since we won't be able to have sex the day before, of, and after ovulation would it be best to do it the day before and after or the day of. He can't get off until he hasn't had sex for a few days so no way we can do it back to back.. I just need help!