Re: Possibly Pregnant
The spotting you are having now could be either related to pregnancy (not necessarily implantation, a lot of women spot in early pregnancy) or from stopping BCPs (I did spot about 4 days after taking my last active BCP when I stopped the pill though I was not pregnant). Like the doc said, you need to go back and retest in a few days. Usually HCG levels of less than 5 are considered negative and greater than 25 are pregnant. The numbers between 5-25 could pretty much go either way--it could be a chemical pregnancy (resulting in early miscarriage) if the beta numbers don't double as they should.
For now, you should consider yourself pregnant until you get the 2nd blood test to confirm.