question

I am 6 weeks according to this app and I had some light pink bleeding and one occasion of red blood at that point I went to the er and they took hormone levels and then less than 48 hrs later they said to come back and get them checked again. after those readings they said everything looked ok and not to worry. So now I made an appointment lime the hospital suggested and they wanted another set of hormone levels from there labs. After those came back the nurse called back and said that according to the tests that I got at the er and with this Dr they are concerned because the levels are not going up as fast as they feel they should... So now I have an ultrasound planned for 4 days from now... has anyone ever had this happen ? and what was some of the concerns?