Josephine, a lady in another thread stated that she had a bfp a while back - on multiple tests (faint I believe).. but she wasn't pregnant. She went to her doctor and it turns out she had a cyst, which was the cause of the positive tests.
If you are on the pill, and using condoms, and there is no way you're pregnant (you stated this throughout the thread)- maybe you should start considering this may be a medical issue that you should get checked out?
Some of your tests are certainly showing two lines - and if there is 0 chance of pregnancy this may be cause for concern.
Hopefully I haven't overstepped my boundaries here.