please help anyone experience this!

I was spotting brown discharge on Monday dr. Sent me for an ultrasound found gestational and yolk sac and no fetal pole measuring 5 weeks 6 days which according to my lmp I was exactly 5 weeks. They are checking my hcg which yesterday was 18082. I get a recheck tomorrow and an ultrasound on Tuesday again. Should they have seen the fetal pole that Early? I am scared and a bit confused....

Thank you for replying I am just a bit worried

My hcg didn't double the doctor didn't seem to worried he is having me go back on Monday for my last draw. Wednesday's was 18082 and today's was 26000

It’s normal not to see a fetal pole that early. My doctor starts getting concerned around 7 weeks if they can’t find one.

Thank you still hoping for a good ultrasound on monday