i have been on sprintec for a long time. probably over a year now. i have had a few missed doses and tred to make up for them when i can. i am usually good about taking them. for some reason i have had 3 period this month and this one started the day before yesterday when i just finshed the 2nd cycle less than a week ago. this is the 3rd cycle in one month. please help. i am already diagnosed anemic. any ideas what this could be and is it the birth control?