hcg levels!?

Yesterday I went for my first ultrasound and blood tests. they told me I'm 6 weeks pregnant and that my hcg levels are very low. 780 to be exact. they said I was about to miscarriage because it was too low. I satrted crying and ny heart was just broken. I'm not bleeding or anything, just some cramps, but I feel ok. They said maybe if the levels go up, there could be a chance of having it but that depend on how high the levels get. I did blood tests today and they told me my hcg levels rise to 1300. Which was like wow, they were impressed. I'm so scared that I might miscarriage. I'm hoping for a miracle because Im so excited for this little diamond. Hopefully I wont. Has anyone been in the same place as me right now?