The most accurate tests claim to have around an 80% accuracy rate five days before your missed period. The day you are supposed to have your period the accuracy goes up and it goes up even further days after your missed period.
You are pregnant
It means that either the blood tests were wrong or the home pregnancy test was wrong
No.
You should have a positive pregnancy test during the entire pregnancy. The hormone levels are the highest from 10 to 14 weeks and a home pregnancy test will be the "strongest" positive then.
No, it cannot.
depends
No, it shouldn't do
You need to wait 3 days or more and take another test or go see the doctor.
there is a 50/50 chance that the test are wrong.
It is possible to get a false positive on a pregnancy test, but highly improbable. I once went in the doctor after taking a home pregnancy test and the doctor basically said that he would not test again, because they use the same test and I was pregnant. But, I did get a false positive as a teenager and the 2nd test was negative. Take a 2nd test.
The morning after pill or emergency contraception will not effect the outcome of a pregnancy test. If you have taken emergency contraception and have had a positive home pregnancy test you are very likely pregnant and should see a Dr.
Yes, home pregnancy tests can produce both false positives and false negatives. If a home pregnancy test is positive, you should see a gynecologist to have the pregnancy confirmed as soon as you can.