Line progression ??

How long did it take for your faint lines to turn into that dark BFP you were looking forward to ? I have tested vvvvfl yesterday and today 11 & 12dpo . When should I expect the line to get darker ? The faint line worries me because I have had two miscarriages, but then again , I have always waited until the day my period was due or later to test 🤔🙄 Trying not to drive myself crazy