My blood test (HCG levels) were 20 @ 11DPO...?

My dr. just called and said it was consistent w/ early pregnancy but wondered if you guys have any input on this. My blood was taken this past Friday @ 11DPo which I know is super early. My period is not even due until tomorrow. I'm going back in tomorrow to keep doing bloodwork. She's monitoring me b/c my last pregnancy ended up w/ a tubal so she wants to keep track of me from the beginning. Any thoughts on this? I'm CAUTIOUSLY excited... Still worried of course! :)