1 day before the NOD test is negative. Is there still a chance?

Hey girls!
I'm new here and had a question.
My partner and I are trying for our first baby.
Last month we used ovulation tests for the first time and got a strong positive on day 11, but unfortunately we didn't get lucky, so I knew it wasn't a success then. This month we also used ovulation tests, the digital CB one, which was positive on day 12 AND day 13, so assuming day 12, my egg should have ovulated on day 14. So we had intercourse during my fertile week, around, on, and after ovulation.
Tomorrow would be my expected period (LH cycle of 12 days).
I tested this morning with WONDFO, and it was negative Do I still have a chance that it could be positive after all? I've had a lot of lower back pain in the last few days, and on and off white milky discharge, plus a pressing menstrual-like feeling in my uterus.

I'd love to hear your thoughts

Love,