Has my timing been off? Positive OPK?

So I have been on provera for 5 months and on clomid for 4. And I ovulated 3 of the 4 cycles according to my 21 day level tests. I do not have normal cycles, hence the provera, but I am still going on day 21 to get my levels checked. Usually my husband and I will BD every other day from day 10-21 and then after day 21, I stop testing w OPKs and don’t keep up with BD. BUT I just took an opk today (day 22) since I have had cramps for about two days (not normal around this time) and it looks positive to me. So has all of my timing been off? I do not have normal cycles, so maybe I ovulate later than most? We have been stopping at day 21 and have not gotten pregnant. Maybe I am stopping too soon? What do you all think? TIA