Hi!
Your hcg levels could be consistent with a very early pregnancy. The best way to find out is to repeat the level (usually about 48 hours later) If the level is increasing, I then ultrasound my patients again. If the level is falling, we know that something is going wrong. I would definitely encourage you to get an appointment with your doctor soon so that you can sort things out!
Good luck!
Dr B
It is possible you could be earlier than they think. Most of the time the doctor will order another ultrasound to about 2 weeks later to follow up. I am an utlrasound tech and that is what my OB doctor does. Everyone ovulates at a different time also so you might just not be showing up on the ultrasound yet. But by your next one it would show and if there is still nothing then it is probably what they call a blighted ovum, which I see a lot where I work. A lot of times people are pregnant for a short time and dont even know it.