Implantation pains or not?

Literally everything I eat makes me super sick! I don't vomit but I certainly feel like I'm going to. At times I feel EXTREMLY hungry so I'll eat but after a few bites the though of eating makes me sick (idk if that makes sense?) Saturday morning I experienced some morning cramping, that night I was bent over in severe pain so bad it made me sick. It only lasted for about 45 minutes then it was gone. My mood swings, attitude everything is off!! My stomach has been severely upset and now I'm having lower back aches. I'm testing negative but AF due on Sept 3rd. I hope this is our mth. Anyone else experience similar issues?