Missed period,negative HPT,and nothing on an OPK 😕

👑Victoria👑 • 11.8.11👫7.23.13 🌈Praying for our Rainbow🌈

I have completely missed my period, which is not normal for me at all and I've been tracking everything for a year. I had every normal PMS symptom like every other month, swollen breasts and my huge pimple on the chin. But she never came. It has been 35 days since the start of my last period. I have normal 28 day cycles. I've taken three cheap pregnancy tests and all have come back negative. I decided to try an OPK to see if maybe it would pick up something...no line registered on except the control line. I've had some mild pinching cramps on my left side that go to the lower left back,all in the hip area. My cervix is high and closed,moist. The day before my period was supposed to start, I had yellow tinted CM. I'm driving myself crazy. Any of you have some ideas or answers for me? I'm desperate. Thanks!

Side note: I am not stressed at all to cause a missed period. Funny thing is, SO and I relaxed this month on TTC and we've had an amazing month.