HELP-15dpo/Cramping like AF is about to show for a week but no bleeding yet

Hi ladies,

I have been TTC for 2 months already. I confirm my ovulation with CB opk kits and with my OB/GYN. I have been spotting after ovulation, cramping and having back pain and thats why I have decided to test at 9dpo and got a BFN. But, everyday after that I have been cramping like AF is about to show and I was so sure that when I wake up I will find bleeding in my pad. This has happened from Monday and on. Ok I thought my mind is tricking me and AF is going to be there its just a matter of time and just when I decided "I will test tomorrow the AF cramping showed up" every night. Now to ease my mind, I will test tomorrow for sure with my morning urine but I wanted to know if there is something to worry about?! I'm very much stressed. I appreciate your answers💌