Late period

My period is late by 9 days. I’m experiencing belly cramps, mood swings, nausea after i eat anything, fatigue, and food aversion. Also my stool keeps bouncing between constipation and Diarrhea. I took a test three days after my period was suppose to start, and it came back negative. Then i waited a few more days and retested and still negative. Waiting until Sunday to test again (I’ll be two weeks late) , but I’d like to hear your thoughts. My cousin says I’m showing signs of early pregnancy, and that the home tests aren’t always accurate. Help!!!