Worried

So yesterday afternoon I noticed some blood on the toilet paper when I used the restroom. It worries me so I went to my local emergency department. According to my last menstrual cycle I should be about 5 weeks along. I haven’t been to my first OBGYN appointment yet. The ER said my hcg was only at 200 which is normal for 1 week but not 5. Then when they did an abdominal and a vaginal ultrasound they said they couldn’t see anything. Has anything similar happened to anyone? Due to past complications I am very worried and very scared. I left a message for my OBGYN but am just waiting to hear back.