Everything seems fine and on schedule

My beta was only 78 at a little after 4 weeks and I'm almost 20 weeks now! The number doesn't matter, just that it goes up

The measurements can be off by a few days this early… don’t forget this is being measured in millimeters— super tiny! You’re probably closer to 4 weeks than 5, so it’s completely appropriate to see what you’re seeing at this point. They shouldn’t be changing your dates with a scan so early, especially when you’re measuring just a few days off from LMP… I’ve never heard of that.