I am 10dpo and got a very faint pos on a home test but neg urine at obgyn office, what is up?

Wait and retest: Your home test as well as the test in office measure the hormone beta HCG in your urine. For these tests to be positive they must reach a certain level. I'd recommend that you wait for a few days and repeat the test in office. The additional time will allow the hormone level to rise and turn the test positive. False positive can occur at home.

B-HCG: Also you may get blood sample for pregnancy test, called b-hcg which is most accurate way.