BDing with inconsistent ovulation
So we have been swaying/ttc since August. I've been charting since January. Thought I had finally got everything figured out. I was Oing on cd 19. But the last few cycles haven't been quite so regular. And I haven't always gotten positive OPKs. I have ovulated anywhere from cd 18-21. In the past I have even ovulated as late as day 30 ( but not in the last 6 months). Me and DH have been BDing every 2-4 days since af, when we get close we usually use a condom until I'm in my fertile window. I don't want to miss O, so is it okay if we BD (unprotected) every 2-3 days until cd 23. So like BD cd 12, 14, 17, 19, 21, 23? Is this too much? Is it bad to BD unprotected that far before O?
And then if I do get a positive OPK should we add an extra BD or something?
Any advice would be appreciated!