I've been taking ortho 777 for more than 6 years with no breakthrough bleeding. Late last year I noticed breakthrough bleeding, so I switched pills not realizing the breakthrough was due to an infection. I took the medicine and recovered from the infection. However, before being diagnosed with the infection, I had my pills chnaged to ortho tri. Well, ortho tri caused severe stomach cramping and clotting so I switched back to ortho 777. Now i've been back on ortho 777 for 3 months and I still get breakthrough. It always comes a week to 12 days before my period and it is dark in color. The closer it gets to my cycle, it starts to clot a little bit. That all being said, when I started the ortho tri, I changed my cycle by a week. Could that be the reason? My body is so use to having period a certain time it is fighting with the pill. Help if you can and thanks so much!!!