Morning sickness before a positive test? Is it even possible? (12dpo-ish)

I’m roughly 12dpo (I don’t temp or use OPKs because I made an agreement with my SO not to “try try” so that’s just glow’s estimate) and I got a negative test this morning (FMU, FRER). My period is due Wednesday and my cycle is usually like clockwork.

However, the last two days I have been crazy nauseous. Nobody else around me has been sick or is sick, just me. I’m also having hot flashes (which I’ve only ever had right before my chemical last month), and I keep getting insanely hungry and then feeling shitty as soon as I eat anything. I’m salivating a lot, but that could just be because of the nausea.

My question is, is it even possible to have morning sickness when you don’t have enough hcg to get a positive test?

What do you think, should I hold on hope or have I probably just picked up a bug?