Should I see a "cheerio" (a white circle in gestational sack) on U/S at 5 weeks and 4 days? Very Scared!

I'm 35 yrs old & had an U/S today at 5 wks & 4 days because I had some brown spotting yesterday. I also had very mild discomfort on left abdomen, but it's not bad.Before I came in the doc said on the phone that she wanted to try to rule out an eptopic pregnancy. During the ultrasound, she didn't say it was normal, nor did she say it was necessarily abnormal. She tried to find the eptopic pregancy, but didn't see anything. She took some blood to check HGC levels and I have to go back in 2 days to give more blood for a comparison. She said if the HGC levels are dropping, then that is a bad sign. I asked if the sack looked normal this time because I saw more in the sack on the U/S than the last pregnancy that didn't work out because I had an anembryonic pregancy that time. She didn't really answer & said sac could be a pseudo sack. Yikes, scary! Question, should I have a white "cheerio" in sac as I didn't see that. Just saw a white little blob in right side of sack. I'm very scared!