Hi Amanda, technically you are supposed to ovulate 14 days before your period. So that being said, it's very hard to determine when you will ovulate... until you already have! I would just recommend to keep using your OPKs to see when you will ovulate. If you don't, you may not get a period. But don't give up. If you keep trying and don't have any luck, see a doctor, they are here to help! SSBD!!!!
I would also say that you may want to save yourself some test strips and cash by starting to test a little bit later. If you usually tend to ovulate that late then it's pointless to test as early as CD6.
Do you keep track of cervical mucous and stuff like that? Sometimes that can be a tell tale sign of when you are close to ovulation.