Birth Control Start Up!

I just got my first pack of birth control a few days after my period ended. My DR told me to do the “Sunday Start” so thats what I planned on doing. Yesterday was Sunday & I started bleeding but wasn’t entirely sure if it was my period. But it was too much to just be “spotting”. So I decided to take the first pill yesterday...Now here I am today & there is absolutely no sign of my period!! Should I have taken that pill!? Will it mess everything up now since I did take it? I’m so lost!