How often should symptoms dissappear??

I'm 7 weeks on Thursday and kinda freaked out.

Ive felt horrible the past two weeks.

I had terrible nausea this morning, took two naps, and then had to keep sitting down while sweeping due to feeling kinda dizzy and "off".

I ate dinner and now suddenly feel almost completely normal, just a bit tired.

Is it normal for symptoms to dissappear out of no where? When should I worry?

So far no bleeding or cramping but I'm still kinda worried.