ectopic or miscarriage

I am so worried right now. My doc just called me and said that my blood level is 4000. Based on LMP i am now 5 weeks 5 days. I had ultrasound yesterday but they did not find anything. So i am going back this Friday to do more blood test and ultrasound. Doc asked if I experienced any heavy bleeding. I never had heavy bleeding only light pink spotting after intercourse. I am so sad and freaking out.