New to birth control (prescribed)

I JUST started taking birth control for the first time. Today was my second day. I took it on the first day of my period! It took away my horrible cramps soon after i took it, hut i was wondering, shouldn’t my period stop? I read somewhere where it said my period could stop. I am only on my second day of period, i dont have a heavy flow but i would say its pretty much normal! Will my period just be shorter this time around? Im just concerned about it NOT stopping lol...

Also another question. My pamphlet said that if i take the pill the first day of my period, means im protected. Thats true right? Just want to double check!!