When will I get my period?

Kayleena
I'm a Sunday starter, and seeing as how I got my period today I just took my first pill of the month (and ever). Since I started taking it on the first day of my period, what does that mean? Will my period still come in three weeks when I start to take the placebo pills or will it come in month since I've never taken birth control and my body will still be getting use to it?