AF due 11/9

I have had off and on cramps since Friday night  the 5th. Still no AF, last cycle I started my period 4 days early. I took a first response test this morning and it was negative. The app says I ovulated on the 27th but I don't think I did until the 31st. I'm so confused and terrified every time I use the bathroom that I will have started my period. 3 days of cramps, is that an early pregnancy symptom? And am I testing negative because I didn't ovulate until the 31st?