How long do these IC take to get darker

[Brunettegurl7]

Got my BRP two days ago but very faint. Today not been much darker . How long do these take to get really dark. I'm using clear and simple test which is 20ml sensitivity.
Cheers all

 

[dinidani]

You should see a progression every 48 hours but loads of things are in affect : concentration amount youve drank how long you have held the dye in the test x