Update on 2nd blood test

Had my second blood test today to confirm pregnancy. My OB says levels are rising appropriately. She also said that it is "still very early in the pregnancy" which makes me feel like she's implying I may miscarry. My period would be due tomorrow so I do know that I tested early. I realize there's not much i can do to prevent that if it's going to happen but obviously this is worrisome. My lastenstrual period started on 8/31 which would make me 3 weeks 5 days. Has anyone else tested positive early and if so how did things turn out?