I went for an ultrasound today because i am in the risk category for ectopic pregnancy. The doctor could not see a sac and she suggested to check the hcg levels.

Is 520 too low at this point? Has anyone experienced something similar?

They will check again the hcg levels on Thursday to see if they are doubling or not.

Is there anything i can do until then? I think i have ovulated late because i saw a very very faint line the day i missed the period. On the positive side the lines are getting darker each day ( yesterday the test line was darker than the control line)