I had unprotected sex on May 5th, according to my Woman's tracker app on my phone it was my most fertile day. Starting the day after May 5th I began having mild cramps, they have been going on for 12 days now. According to everything I've read you cannot have pregnancy symptoms that soon, but since I was ovulating when I had sex I am very worried. I am due to start my period any day now. I've taken two pregnancy tests in the past couple weeks and both were negative. Is there any possibility I could be pregnant? If not, what else could cause this?