What causes the color change in a pregnancy test?
The test zone contains different antibodies which are attached to the strip and unable to move. These antibodies also bind to hCG, creating something of a hCG sandwich between the two different antibodies. The enzyme on the mobile antibodies triggers a colour change in dye molecules on the test strip.
What color does a pregnancy test turn?
Pregnancy test 101
Home pregnancy tests detect a hormone called human Chorionic Gonadotropin (hCG). hCG is released into the body when an embryo has been implanted in the uterine wall. If hCG is detected, a test line (pink or blue, depending on the test) will appear.
Do pregnancy tests get darker each day?
Although hCG levels increase exponentially during early pregnancy, that doesn’t mean that the pregnancy test line will necessarily get darker as each day passes.
Why did my Clear Blue pregnancy test turn pink?
The Colour Change Tip will quickly turn pink, showing that urine is being absorbed, but it’s important to continue to hold it in the urine for the full 5 seconds. Keep the Colour Change Tip pointing downwards or lie the Test Stick flat until the line has appeared in the Control Window.
How dark should a pregnancy test line be at 3 weeks 5 days?
3 weeks: 5 – 50 mIU/ml. 4 weeks: 5 – 426 mIU/ml. 5 weeks: 18 – 7,340 mIU/ml. 6 weeks: 1,080 – 56,500 mIU/ml.
Why is my pregnancy test lighter in the evening?
Your urine will likely be more diluted at night than in the morning. Having more concentrated urine is one of the benefits of taking your pregnancy test in the morning. Taking the test too early. hCG levels need time to rise enough to be detected by a home pregnancy test.
Does the darkness of the line on a pregnancy test matter?
The darker line is usually the control line. Sometimes this second line is so faint, you can barely see it. If there is a line, not an evaporation line, but a true line, no matter how light, you should read that as a positive pregnancy test.