help!

So I took a test faint lines they said I was pregnant I had taken one a week before negative I had to go to the e.r a week after finding out due to severe nausea I don't know my exact dates because I was on bc stopped had a period took birth control same day to stop stopped bc again after two days had bleeding again and so I'm unsure of exact lump they seen a sac but said my hcg levels were 179 and to get a test in a couple days too see if they go up that they were low for the dates I gave them but with all the birth control mix up I could be way off for limp or ovulation I looked it up online and most women with miscarriage problems said like 4 weeks their hcg levels were like 20 so if it's just barely a week since my positive test do you think I'm okay and just stressing? I don't want to go in for another hcg test because I feel like maybe I'm just totally off with the dates and maybe only a couple weeks off has anyone has anything similar happen?