Birth Control

So I’m almost done with my pack, I just need Saturday’s pill tomorrow & I’ll start a new pack but this pack I have missed 3, not in a row but like weekly almost is that bad? Should I call my doctor ? Also how do I know my pill is working, I’ve been on the same brand since April 7th & I just don’t know if it’s effective. Lol I don’t get my period bc it doesn’t come w placebo pills? So idk if I should stop a week to get my period or just continue to take it the way I have been.. can someone help! Lol