4 weeks and spotting

Hey ladies.. I just recently found out I was prego! I started to have cramps but not really bad ones and started to spot two days ago... I went to the er and they took blood, urine , and did a vaginal ultrasound... Results came in they couldn't see anything in the ultrasound my hcg level was 500 and urine test was positive they did find a small cyst in my ovaries...the doctor tolde I would be in danger of a miscarriage, I can be really early in the pregnancy or have a ectopic pregnancy ... She told me to come back in two days to see my levels again.. I'm so stresses and really sad idk what to do think... Anybody have this problem?