is AF always 14 dpo (give or take)? please help.

I had a positive opk on cycle day 16 and then again on cycle day 21. Which doesn't make much sence to me. I'm currently on cycle day 35 and just came off birth control last month. I'm guessing that's why my cycle is long. Say I didn't actually ovulate the first time, and my body did the second time. Would my period start 14 (give or take) dpo? Or is it possible to ovulate right before a period? I have taken several hpt test since I am technically late but all were negative. What do y'all think? Still no AF.  I'm just getting a little anxious.