How many of you ladies have had a unnecessary scary misleading first scan

I've had 2 miscarriages before concieving again so I was put on progesterone and had an early scan around 6 weeks but all they could see was an empty sac but my hcg is rising.

Also it scared me even more that I didn't really have any symptoms but now I've been dry heaving for 3 days and also headaches

How many have had early scan but was actually more earlier than thought that's what I'm hoping