How much darker should it be?

Liz

Okay, so I used an ovulation test strips yesterday for the first time. It was pretty dark, however today it looks a little darker. My question is how much darker should it get or is this perfect? I bd yesterday and the day before. Hoping to be again today... work schedule gets in the way. Should I be good having done it previous two days (hoping today)? Here are my pics.. the 13th and the 14th. Let me know ladies!! Thanks