So my last period was June 28th and I had it very light and only for four days. My period was due on July 26th and still no show. I ovulated on 10th and 11th of July. I have a constant back ache and cramping in my stomach. When I eat something my stomach is still growling once I've ate. I can't wear a bra because my boobs are insanely sore. I tested on my 3rd day late and got negative. What do I do ???