5 weeks 6 days pregnant but HCG levels are 8-9 weeks

I went to the emergency room yesterday for severe nausea and headache and was told I was dehydrated. I was given some fluids. I got a vaginal ultrasound and was told the yolk and gestational sac were there. That measured out to 5 weeks 5 days. Which doesn’t worry me! But what worried me was my HCG levels. Anyone able to relate? Or have any input? My obgyn isn’t open till tomorrow and I have yet to have my first visit because I’m still so early. I’m trying not to worry. I’m still currently in bed sick and trying to keep hydrated. God bless ♥️