I am a bit concerned that your period came that early as the hormones in Yasmin should have regulated the cycle a bit better than that. From what you have told me, I think it is unlikely that you are pregnant, however the plan B pill is not 100% and by taking it nearly 48 hours after intercourse its effctiveness is down to about 80%. Having said that, you should not have been ovulating due to the yasmin.
My thought is that you do need to see your doctor to dicuss how you get your cycle back on track. I think you should skip the sugar pills this time around, but get your doctors permission. This will mean you don't have a period at the end of this pack, but that should be okay. But talk to your doctor first, just in case they want to run a blood test for hormone levels first.
Regards
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