How do the doctors urine pregnant tests work do they go by colour or number of lines...

[Lindsay]

...like the home ones do. S? So what I mean is, are they one line for negative and two lines for positive or blue for negative and pink for positive? Just I was given one to take home and it came up with a pink (bright pink) line so what does that mean? Cause yes it was pink but it was also only one line! Please help me by telling me how do they read them