Ate fast food 4 hours ago and now have stomach cramps and diarrhea?

Roughly about 4 hours ago myself my husband and our son stopped for fast food. I know I know bad choice we very RARELY eat fast food but we had a very chaotic day and didn't want to wait to get home to make dinner. Anyway everything looked smelled and tasted just fine. It's been about four hours now and I'm having really bad stomach cramps and diarrhea on and off. Is 4 hours after eating something to soon to feel these effects? Another strange thing is my husband and son aren't sick at all. I'm not vomiting but my stomach is killing me! Maybe it's just me and it wasn't the meal I ate? Because again my husband and child feel fine and they ate there with me. Just wondering again is 4 hours after eating to soon to feel these effects? Thanks! Never eating fast food again!