How to dtd for the next cycle?

Just want your opinion on when to dtd for my next cycle. Has been ttc a boy for 7 months without success. My cycle has been very regular, about 29 days for the past 4 months. Always get my positive opk on cd14, and O on cd16. LP always stay for 13 days. For the past cycles, dtd on cd13, cd14, cd 15. Normally get 1 or 2 days of +opk and O third days from first+opk. Opk turn negative on cd15, but O on ch16. Is that normal? Me and husband both 40 years old. Husband can't do more then 2-3 days of continue dtd., should we just dtd on day after +opk and next day which -1 and O?

What I would do is have you guys DTD unprotected every 4 days, then in addition to that I would have you have 3 attempts right around your positive OPK. The night of the pos OPK, the next morning if he can, and then agauin the next night.

Are you doing anything else like baking soda or egg white?

Thank you Atomic! No, we are not doing baking soda or egg white. I did use preseed. If I do the three attempts right round positive OPK, but I O 2 days after first +opk, would that mean I dtd on -2 and -1 only? That is how I dtd before. Should I try to skip the night of +opk and do next morning of +opk, night and next night?

Well, the problem is that we can't be totally sure when you are ovulating, and I am worried that you are starting too far out (and I couldn't really tell that from your original post, I'm sorry). And then by the time the egg shows up, your husband is shooting mostly "dust" as we jokingly call it.

What I think we need to do is push it closer to ovulation - avoid 3 days before O because nothing is probably going to be left by then. 2 days before O has good odds of conception but also that doesn't seem to be working for you guys. My thinking is that any time the day before O and early in the day on O day may be better odds for you guys, if that makes sense.

Thank you for your suggestion. We will try to dtd every 3-4 day and attempt on -1 and O. Do you think I should do morning and night on -1 and night on O?

yes if possible or night on O-1 and morning/night on O day