I take my pill religiously and almost always get my period on either tuesday night or wednesday morning, it is now sunday and still no period. I always get the same signs before I get my period like certain cramps. I got them this time but no period. I just got back to college and have had some stress and I missed my period around the same time last year and was not pregnant. should I be worried or is this once a year missing my period normal. I also switched brands of BC but it is the same hormonal amount each week. Please let me know