Where's my period? 👀👀

Idk what's going on So I'll make this short and simple.

My periods are like clock work but last month it was a week late. However this month it's completely mia. I've taken a test and it says negative and I take my temp faithfully everyday when I wake up but it's been fluctuating this whole time. On a scale 1 to 10 I'm at a 15 with how nauseous I am it's ridiculous and its all the time. My back and side hurts and I do have minor headaches. I eat a lot but I love food so Idk if that's a factor lol

Any comments what y'all think?