I missed the first week of birth control

I ordered my birth control the day I started my placebo pills, after a week (I ran out Friday) I had unprotected sex (Saturday and Sunday). Because we thought they were going to arrive. The following Monday, I get a call saying they haven't shipped it because the payment didn't go through. I checked, they haven't taken the money. Then they finally took the money and the pills won't be here until sometime Friday. So that's one week without birth control. This should be the start of my fourth month. My question, should I be alright? Since I've taken 3 months worth and should start taking them again on Friday? Has anyone gotten pregnant directly after missing a week?