10 days late....positive then negative hpt?

Well hopefully being 10 days late is a GREAT sign. If you definately read the test results within the "time window" (usually 10 minutes, no later than 10 minutes otherwise it is NOT considered a valid test result anymore), and it showed positive then it is definately positive. This pattern you mention could be from taking a couple test getting BFP, and if you tested again to soon afterwards or drank alot of liquid in between those test it most likely would show up negative, especially early on, your body has to build it up to have a concentrated level for the HPT to detect. It sounds like you are experiencing early preg symptoms though. Also something else to keep in mind is this: If you took a test, read the results within the 10 minute time window, and it was positive, and then you went back and it looks real faded, it is because once the hormone is detected the result will fade a little sometimes all together. That part is on the chemicals in the test that detect HCG. I would give it a couple more days and if you are officially 2 weeks late, (14 days) and still no AF test again. If it comes back BFP then congratulations & go see your DR, if not I would go see my DR anyways and find out what is going on in there. Good luck, hope you get what you are looking for.