My period was absent may and June it showed up July 23 regular period last 4 days according to <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> my next period started August 20 around the 10th of August I spotted a few hours then stop I also been cramping bad for. Two days now I usually dont cramps I tested again and negative again felt cramping in my stomach left side this app said I ovulated last week what is going on can anyone explain it