Had scan today, doctor asked had i any pain or bleeding before the scan, i said nope just awful sickness.

She explained my hormone had dropped so said lets get scan done and see if anything is growing! So i was panicking but scan was good baby measuring 8w 4d and has a good heartbeat. I was just wondering if this has happened to anyone else? I know babys fine i seen the heart but just concerned my level had dropped. I dont have another scan until 21st oct so was hoping someone might have some reassurance xx