Did we finally do it?

I'm 32 and my boyfriend is 39 and we have been ttc for over a year and a half. That being said, he has problems with ejaculation during intercourse (he usually can only ejaculate with oral/hand stimulation, and even then it's not every time). He successfully ejaculated during intercourse on my peak ovulation day and I want to know if we have any sort of slim chance to conceive. My question is, can we still conceive if he hasn't ejaculated in over a month? I have scoured the internet but haven't found specifically what I'm researching. Anyone have any insight on this?