Birth control effectiveness?

So I’m on a 21 day birth control so I take no pills for the week I get my period. I started thinking about it and doesn’t that mean I’m not protected for the week I’m on my period? I know you’re least fertile around that time but isn’t it super risky? And if I’m not taking a pill for a week aren’t I not protected for a week when I start taking pills again? So that’s 2 weeks out of 4 that I’m not protected. Am I wrong or is this awful birth control?