opk, with a back story

Hey ladies, currently cd 26, last month af came on cd25. So I tested yesterday morning, bfn. I did get a few VVFL last week so, was thinking lines should get darker. I have been taking premama this month (maybe why my periods are getting longer) I usually spot a few days before AF. And so far nothing. Had some cramping off an on a few days ago, but today nothing. Do feel headachy, and my lower back hurts. Cloudy stretchy CM, had that a few times before AF in our 14 months ttc and was hoping it meant something. But it's just normal for me. Follow up appt next Monday with fertility doc so I guess I'll find out then if af hasn't shown. Took an ovulation kit because I promised myself I wouldn't spend anymore on got this month. And one looks pretty positive. Is it true you get an LH surge before AF? Still holding on to hope. Anyone use opk as a hpt and it turned out to be a BFP? Any advice or comments are appreciated! 🌈 ✨💖