Confused! Why is this one faint?!

I took 5 pregnancy tests all within a week. First was a pink dye on day of period due and got a faint but clear positive. 2nd was 4 days later, blue dye, also positive and was taken in the evening, 3rd was next morning urine and got a positive that looked like the nights before, 4th was taken last night and was stronger and line was thicker and 5th was taken this morning (just now) but it isn’t as dark as the others. It’s very faint, definitely there, but much fainter than the others but as thick as last nights also. Why is this? I did have a glass of milk before bed and didn’t wee it out till this morning when taking the test so could that be it? Is it too diluted? My wee was green so does that mean anything? Am I losing this pregnancy? Please help! TIA