Measuring too far behind?

Here’s the thing. I’m pregnant and supposed to be 8 weeks along. I started bleeding really badly and went to the hospital where they said I had a subchorionic hemorrhage.

Here’s where it gets tricky.

My baby is only measuring 6 weeks.

However there’s no way I’m only 6 weeks because I haven’t had sex in quite some time and I got my BFP on December 31st😭

Has anyone measured 2 weeks behind in the beginning and their baby totally been ok?

It’s hard to not worry whenever I’ve already had one miscarriage that started exactly like this, measuring behind, and bleeding.

Editing to add my baby had a heart beat yesterday of 122