Faint positive?

Hi lovelies, 

I am new to this the forum and Ttc! 

Yesterday I was 9dpo and decided to test using a clear blue  (+ / -) test. When I took the test around 8.30am it appeared to be negative but upon inspection I thought I could see very very faint line. I took it to work checked again at 10.30 and it looked to have a blue horizontal line which looks to me like a faint positive.. i got home and dug out the previous days negative and it had also turned to look positve and tonight again i thought I had an extremely light line almost non existant that has darkened / coloured slightly over about 4 hours.. anyway to cut a long story short I have tested with cheaper tests and don't have any faint lines neither In the alloted time or hours later.

These 3 tests are baffling me. I am aware you should disregard any result after so long but have also read a coloured line can only be from the hcg  hormone so maybe I'm early pregnant and it's taking the test longer to develop a reaction ?? 

Tia for any help!!