10 weeks and scared

So... long story short. I got my first ultrasound at 5.5 weeks. They just saw the sac and yolk sac. Next ultrasound 8.2 weeks and baby was there measuring 8 weeks and with a heart beat of 172. All was good till 6 days later I started to have pain on my left side and called my OB. She was on vacation and the assistant told me to go to the ER so I did.... all was good. Supposedly 9 weeks baby measuring 8.6 weeks. Heart beat was 170 ( is it normal that in 6 days in went down 2 ?)

Anyway.... my morning sickness ( all day sickness) have been horrible. Specially the past week. But yesterday, exactly 10 weeks I woke up feeling nothing actually feeling so HUNGRY ( i have lost 7 pounds in this pregnancy). It scares me to read that this can be because my body is not producing more hormones and it could be a missed miscarriage. Any ideas?