HCG levels

Hello everyone! So I'm just looking for some positive stories. I had a miscarriage during my last pregnancy in 2012. I'm pregnant again. Currently 7 weeks and 5 days. Well when I was 6 weeks and 2 days (SUNDAY APRIL 3rd), I started bleeding and I went to the ER. They checked my HCG levels, which were 7,290 and also did a trans vaginal ultrasound and baby was measuring 6 weeks 0 days and heartbeat was 116. I only bled for about 24 hours and it turned from red to brown blood rather quickly. They said it was a threatened miacarriage. I repeated my HCG levels about 36 hours later (TUESDAY APRIL 5th) and it went up to 10,000. I've had no bleeding since, but they had me repeat HCG levels again after one week exactly (TUESDAY APRIL 11th) and it had only risen to 27,000. I had read that once it's past 6,000, it could take over 96 hours to double, so I'm trying to remain calm and hopeful! It just seemed low to me. I know it's good it's gone up though.  I go on Monday for another ultrasound. Please ladies tell me good experiences! :)