I've been on birth control for five months now, three on Ortho. Every month I've experienced my 'period' on my last active week, but when it comes to taking my inactive pills I get no bleeding what so ever. Why does this happen? I take my pills at 8:30 everyday. Do I need to change birth controls to fix my problem? Exercise doesn't help or delay this from happening on the third week- it occurs a few hours after I take the pill.