HCG not going up but fetus bigger?

So I found out I'm prego 10/15 on the 21 I started bleeding brown blood. Went to ER my HCG was 4042 ultrasound showed little sac but no HB. Went to my doc ob10/23 HCG was 3961 but nothing was happening. Doc told me to come back Monday to recheck HCG it was 4062. Doc is now confused and said recheck Tuesday and it was 3915. I went to see her today she did ultrasound and now the yolk sac is formed I could see it was much bigger and I could see the fetus today but still no HB. She said she wants to another ultrasound and blood next Wed to finally see what's up. She said it's probably to early and small for HB. I don't know! I'm so confused and uncomfortable. Does this make sense to anyone? Any input or experience would be appreciated!?