Obviously it's possible.... but is this?

I asked a question a couple of weeks ago wondering if it was possible to be pregnant after switching from Depo to Yasmin but being on an antibiotic when I did, most of you answered yes it's possible but not likely wait to see if you miss your period. So I started taking the blank pills last Saturday and still no period, periodically I get cramps, my are starting to kill me but I start a new pack of Yasmin of Saturday. So yes I still know it's possible that I'm pregnant, but is it possible that the first month switching from Depo to Yasmin that I would skip my period all together? I have never had that happen before. I Never had my period stop on Depo, it made my period 2 weeks long,the whole time, it was horrible! My doctor said I must be the 20% of women that will never get lucky enough to have Deop or Seasonal or Seasonique work. Should I just relax, or based on the previous answers I got now that I have pretty much missed my period should I be worried? Thanks guys!