its possible you are pregnant and just not metabolizing the hCG
however, its more likely that you just havent ovulated on time this month and it could be a while until AF shows yet.
Some doctors offices would let you come in for a blood test at this point... all would if you do not mention that you have taken tests but they would likely just give you a urine test... which would be less sensitive than home tests in most cases.
Other doctors say not to come in until you miss your second period without a positive pregnancy test. The only way to know which your doctors office is is to call them and find out.
however, its more likely that you just havent ovulated on time this month and it could be a while until AF shows yet.
Some doctors offices would let you come in for a blood test at this point... all would if you do not mention that you have taken tests but they would likely just give you a urine test... which would be less sensitive than home tests in most cases.
Other doctors say not to come in until you miss your second period without a positive pregnancy test. The only way to know which your doctors office is is to call them and find out.