What are the chances of getting a false positive on a pregnancy test?

My friend reckons she has got TWO at the doctors!!





I think she is lying.





Has anyone ever had even ONE before? Chances of getting two is pretty rare, right?What are the chances of getting a false positive on a pregnancy test?
I took a pregnancy test early in the morning as suggested and it was positive. I took another the next day to be sure, and it came back negative. I decided to wait a bit before going to a doctor, and 3 days later my period arrived. So yes it is possible to get a false positive.


Also this website says if you wait too long to read your results, it can result in a false positive!What are the chances of getting a false positive on a pregnancy test?
here could be various reasons for a false positive test.





Chemical Pregnancy


A chemical pregnancy is basically an early miscarriage. Research has shown that half of all first pregnancies end in miscarriage. Due to the high sensitivity of home pregnancy tests, many women catch early pregnancies but end up going on to have their periods due to a chemical pregnancy.





Missed Reaction Time


For accuracy in home pregnancy tests it is essential that you read the test results in the stipulated reaction time. If you let the test sit for too long (after the instructions on the box tell you), the test is invalid. This may cause it to show false positive results.





Chemical Interference


Drugs that have the pregnancy hormone Human Chorionic Gonadotropin (hCG) in them can cause incorrect results in home pregnancy tests. The Human Chorionic Gonadotropin (hCG) in them may be responsible for the false positive pregnancy test. If you have had an HCG shot due to infertilty treatments, you need to be sure the shot is out of your system before you attempt to use early pregnancy tests.





Evaporation Lines


While technically not a true pregnancy, some pregnancy tests leave a faint evaporation line as the urine crosses the test. This faint very light grey evaporation line in the test area is often interpretted as a positive result.





AimStrip pregnancy test strips have a very good reputation of NOT leaving evaporation lines and are much less expensive than brands you can buy in your local supermarket or drug store.





If you are not sure about your home pregnancy results it is recommended that you try again after a couple of days. If doubts regarding the results still persist, you must see a doctor for a pregnancy blood test. A blood test administered by your doctor is more sensitive than the early home tests and can be taken between seven and twelve days after you conceive.
I had 4 false positives before they sent me for a scan to see if i was pregnant as i kept getting mixed results and it seems they were caused by a hormonal imbalance, i had never been pregnant at that point and had PCOS. So it definateley can happen, i even showed the doctors the tests that i had so i could prove it!!
no you carnt have a false positive you can only have false negs