Birth Control and Bleeding

Hi i just started using birth control a few weeks ago and i’m ending week 3 of pills, a couple days after my period ended. Before starting the pill, my period began to be irregular and started to be 19 to 22 days apart. Since i just started birth control my period (when i normally expected it to come on this app) was late and i’m not sure if it’s because of the birth control starting to regulate it. I’m just worried if it’s other factors, like sex, or truly just the birth control doing its job. (i also heard that your period is supposed to start when you take the sugar pills or the pills that are a different color than the other weeks, maybe that’s another thing that’s worrying me since i haven’t started to week of pills yet) Any feedback is welcome please!