Brown spotting at 8 weeks???

I woke up today with brown spotting, I'm 8 weeks +...   I went to ER they did sonogram and blood work, everything came back fine, the baby is ok, but I'm in risk to have a miscarriage, I have to stay in bed and go back to repeat the blood work in 2 days....  Sometimes like this happened to any of you girls, I hope is not bad, and it was just a false alarm.. I'm so scared.. Thank you