Other "false positives" come from misreading the test, leaving the test and coming back to it, or digging it out of the trash hours later. Pretty much all HPTs these days are designed to be read within the first 10 minutes. If a line shows up after that, it doesn't count.
Rarely. Two in a row are practically unheard of, assuming you aren't using fertility drugs. (I know of one or two test brands that are not considered trustworthy though.)
Usually when a woman reports a "false positive" because she got her period it's attributable to chemical pregnancy. This happens when the test detects an embryo that fails to implant properly. The test shows positive but baby doesn't "stick" and mom gets her period within a few days.
You'd be about 6 weeks pregnant now, so definitely should be showing positive in most cases.
Ok mines was nov 15 and I was able to test on dec 14. By that time I already had symptoms and tested three times all positive.. Wait another week and test again, but some women to test accurately on urine, so blood would be better
When was your last period