Possibly pregnant

Ma

I’m 9 weeks pp and I have been feeling nauseous at times, cramping for a few days was told I was dehydrated so I chugged water for two days and my cramping is pretty much gone. But my stomach just feels off.

How would I know if I was pregnant this early after having a baby?😭 if I took a test are my HCG levels still in my system? I thought my period was coming but it hasn’t anyone have the same symptoms?