What is going on 🤔

So ive posted before im now 15 days late fot AF, had low stomach cramps on and off for 2 weeks, low back pain, v.sore boobs with shooting pains in/around nipples this last week, today started with dark ? Blood in my underwear, a very small amount, so i thought well here comes AF but however nothing, instead clear stringly CM..so i took 2 more ovulation sticks after doing them each day and they are completely negative! I have no idea whats going on ive done preg tests and theyre negative