hot flashes and nausea?opinion p

negative test four days ago, period one day late,waiting to re- test.

each evening every night for the past week at almost exactly 5pm I get these big hot flashes and waves of nausea, can last up to a few minutes and leaves with a headache, I'm also exhausted by 8pm every night despite action.

not TTC but not actively using protection either.

Just wanted to know if this could be a sign of pregnancy or if anyone has experienced thisI have no idea what else it could be.