I been on birth control ortho-tri-cyclon-lo since i was 16 and it worked just fine.My periods was coming on on time and usually for 4 to 5 days.Im 18 now and started college August of last year 2009.My schedule was different day by day which caused to miss days,i couldnt keep track and remember to take my pills so i stopped taking them.After that 4 months passed and no period also having unprotected sex with my boyfriend (If that helps).The fifth month came and my period reappeared for nearly 2 weeks.Now that the 6th month is here and almost over it havent came on at all.Ive took several pregnancy test and doctor pregancy test also but they all came back negative. Whats going on or should i start bc up again to see if it start to regulate my periods again????PLEASE HELP ME!!!!!!! %-)