Faint positive yesterday but very dark line today

These are all three different test taking between yesterday & today. The blue dye test was taken yesterday & the pink dye test were taken today, all later on in the day. My last period was December 19th, at least i thought it was a period, it lasted for about 5-6 days. I don’t remember the consistency of my flow. Is it true that the darker the line the further along you’re in the pregnancy??