I ve changed my previous pills to yasmin for 3 months now. My last period was strange, it came some hours late then usual and it was few. In the second day it was slowly getting heavier until the the night when I realize it was a much better amount, but still less then the usual. My third day feel like normal, just a little less then usual. Finally in my last day it was finished by lunchtime. I have a boyfriend and we had unprotected sex a week before the period, he most probably didn t finished inside, before that week we didnt had sex at all ... I m worried for the reason of that irregularity, since my periods were always very punctual and regular. What do you think could be the cause of this? By the way I am 18 years old and ideal weight, I took all my pills and on time. Thank you!