Missing the 3rd week of birth control-Start new pack. .or finish and then start new?

Hello! Ok, so I would rather not get pregnant which of course is why I am on the pill. I very rarely ever miss active pills. However, lately I have stopped taking the last week of my set because it doesn't matter anyway,(I know, I shouldn't have, I've learned my lesson I promise) I get my period and then start a new pack that Sunday. Well... somehow this past week I did something awful, I just thought for some reason my period was supposed to be this past week so I just stopped my pills as if it was and decided to start the new pack at the end of the week.(like I normally did) But I looked on Thursday and realized that I had in fact missed the whole third week of my pills. I freaked out a little bit but not very much because my period started the same exact time of the week as it would if I had taken the 3rd week.(the day before, which was wednesday) So I know my chances of bing pregnant of course are almost nonexistent. I had a friend tell me I should start my third week on Sunday then go right into my new pack after that and that I hadn't really messed up very much. I've looked online again and again and most say the same thing: That I must use back up measures for 7 days to make sure I don't get pregnant. But on the matter of taking the 3rd week. . or throwing it out and just starting a new pack is a little confusing. There is not really anyone I can talk to about this so any advice or experience that you once had or heard of would be appreciated. I have till tomorrow night to figure out what I'm going to do. . So to recap, I have the whole 3rd week of pills, AND a new pack. Should I start the new pack like normal?. . or start the 3rd week then after I've taken the active pills go right into the new pack? (I would prefer to do the 2nd option, but of course only if its the best, also it seemed that most websites said to do that. . but because I have had my period I don't know if that changes things)