NuvaRing and odds

I am on the nuvaring, but I am not having the same complications that everyone else seems to have. I have been on the nuvaring for about three and a half years. Everything seemed to be going great with this new birth control until about 4 months ago when i didn't start my period. So, my fiance and i decided to get a pregnancy test and sure enough it was positive. With me being in my third year of college and having to change our wedding date, our lives have taken a drastic turn.Now that i am 18 weeks pregnant i am trying to keep a close look out on any other nuvaring pregnancies. I had found 2 others around my area who were having the same problem as me, so i knew i was not alone. Then the most shocking news came to me when my brothers girl friend called me one morning telling me she hadn't started her period yet. She was on the nuvaring too, let me remind you. The odds of her and I both getting pregnant on a birth control that is 99.9% accurate is a 1 and a million chance. What are the odds of that? Sure enough she is pregnant too. So our question is, was there a bad lot of nuvarings sent out around the same areas or what? And its not like we misused them either. we have both been on it for a long time, so we know the do's and don'ts. So, id there anyone else out there with this problem?