If pregnancy urine test is in valid what is the result means 1 line appear after some time disappear?

See answer details.: A home urine pregnancy test can be 'invalid' for several reasons; the test strip may have become corrupted (heat, humidity, etc) or the urine specimen may have an interfering substance. Check the expiration date of the test and repeat with a new test kit. If the results are still 'invalid', see your family physician or ob/gyn for a quantitative HCG test performed in a lab.

Follow Directions: Urine pregnancy tests have a test result and a control result. The control line should always show up-- if it doesn't the test is invalid and should be repeated with a new test. There is also a specific time frame to read the result-- usually 3-5 min. Follow the result that is present at the appropriate time to read the test.