Preg Test

That evaporation line is not going to show color. It may be the slightest gray, as if the line isn't even there. You have to get in very BRIGHT light to see it. I've been pregnant 7 times and taken tests very early many times. If there is color to the line, even the faintest...blue or pink depending on the test, then it's not an evaporation line. If you are running around from light to light trying to see it, consider it negative. If it's obvious, colored, but faint, congrats :)

Because after 10 minutes the pregnancy line will show up due to evaporation. It's not a positive but an "evaporation line." She would need a new test. Encourage her to get a digital test that says "Pregnant" or "Not Pregnant." Or encourage her to go to her OB on Tuesday to get a blood test. That's the best test to do anyway... having the OB test blood.

It's so the manufacturer's can continue to claim their accuracy rates. A pregnancy test that is positive may have the line fade out and go away after time, though it's usually longer than 10 minutes.

because the test chemicals can change...making a negative appear positive....once positive it won't change, however, a negative can turn into a false positive

Because these things called evaporation lines can appear and it can seem like a positive, when in fact it is negative. If the test was positive, you can save it, the positive lines will be there regardless. However I will say my mom used to work in a pregnancy center and one time they gave a girl a test and it showed negative. When my mom was cleaning up about thirty minutes later, she saw a faint line, and the had the girl back in a week or so later and she was in fact pregnant. The best thing to do is observe the time limit and retest in a few days or a week to be sure, if the test is negative of course. A positive test is almost always right :D

I don't know.
Maybe it will lie to you or change.

I just wanted to let you know that the really cheap tests are just as good.
The last preg. test I had to use was from the dallor tree - and they were $1 each. Before - years ago I always used the $10 ones
What a waste of money.

Take care.