peak hcg?

Can your hcg peak before 8-10 weeks? I have had severe "morning sickness" for the past 10 days now I wake up today and I feel fine. My hcg level were extremely high from the beginning so high that the docs were convinced it was multiples. I am now 7 weeks and 1 day and I am freaking out that I am not really sick right now. I have an ultrasound today but I just wanted some insight on other ladies experience. Also this is an ultrasound from 6 weeks 5 days. I see white lines with the yolk sac I heard that is the placenta forming.