Help!! 😭😭😭 scared mom here

Alyssa β€’

Alright mamas I need your help/opinion/experience pleaseeee! So I am somewhere in week 5 of pregnancy, I was thinking 5 weeks 5 days but that’s an estimate bc my cycles have been WILD. Well yesterday I had quite a bit of BROWN SPOTTING. I freaked out of course. Called my doctor and they said only go in if it turns red. Because of my history, I was freaking out and went to the hospital to get checked anyways. They did and ultrasound and blood work. On Monday May 20th my HCG was 171 and yesterday it was 6,809! WAY more than doubled BUT they did an ultrasound too. They saw a gestational sac and a yolk sac. Gestational sac measured 1.8 cm and they said that was estimating me at 4 weeks and one day. I thought this was weird bc you CANNOT see a yolk sac at 4 weeks. I looked up the measurement and it says 1.8 cm is about 6 weeks πŸ€” am I confused? Please help me understand. I will attach pictures. Please tell me your experience bc I’m terrified. Still having brown spotting but it’s slowing down...