Is first BFP at 17 DPO an indicator of ectopic?

Annie

Got my first BFP at 17 DPO after testing everysingle day for two weeks. When I went to the doctor to confirm it two days later, my HCG was at 20. One week later my HCG was at 500. My doctor wants me to come in for an ultrasound on Friday because he’s worried it could be ectopic based on my numbers. He didn’t say he necessarily think it’s ectopic, just that it could be. So now I have six days to drive myself crazy wondering if it is or isn’t. Any advice? Anyone have similar experiences?