my sis took 2 pregnancy tests and you can see a faint line on the second line, both of them where the same, and these test were like the 7 dollar tests, then i bought her a $10 digital one and it said "not pregnant".
i'm not really sure what to think about this because the first two you can clearly see the lines both of them but the digital one said that she is not??? what the crap!?
If she's testing too early after sex then that could cause problems. She needs to be 14 days past the last act of unprotected sex, because it takes up to two weeks to become fully pregnant! As others have said, use first morning urine. Dollar store tests are just fine; they work just as well as expensive ones.
it's more likely to have a false negative then a false positive, especially twice. I would agree with waiting a few more days then trying again. I only took one test, and it wasn't completely clear on the second line, but I'm now 20wks along.
Many digital tests tend to be less sensitive than the line tests. It requires a higher concentration of hCG to trip a digital test to read "pregnant" versus a line test, especially if she was using a more sensitive non-digital test (usually these are "early" result type tests and say results 5 days sooner on the box).