As of today I'm late for the first time in years. The last few day I've had a few signs my period is going to start but the aren't normal for example I have some cramps but they are mostly in my back and on the left side of my pelvis where I assume my left ovary is. I've also had minor pink and brown spotting but I had to really look for it before it stopped. My normal boob pain is also absent they feel fine. Also the last few nights I've had nausea just show up at night and I can get it to get better by laying down but as soon as I get up it comes right back. I've taken 5 pregnancy tests (2 digital clear blue and three test strips) all negative. What's happening?