What the heck is happening

So for the past week and a half I've been cramping on and off like my period is coming according to the app it was supposed to come Monday. It still hasn't. I've had a lot of gass lately too and yesterday and more today I've had random stomach pains. I'm worried now because last night I woke up in a sweat and with the absolute worst cramps I've ever had (and my period cramps are the worst) and I had to urge to go to the bathroom so I went and had diarrhea. I was able to go back to sleep for a while. And today my stomach has still been hurting. I've felt dizzy a few times. I've had a lot of heartburn too. I've had no blood or spotting at all random cramps thru the day and I've been hungry and wanting to eat normally though.