An irregular period like the one that you are experiencing is not normal... but it doesnât indicate a serious medical condition, either. When using birth control pills, women experience a "period" when taking the last 7 inactive pills. Missing one pill can cause the hormone levels to go down and provoke vaginal bleeding. If the cause for bleeding is a decrease in hormone levels, the bleeding should stop upon continued consumption of the pills. If you missed one pill, take 2 pills the next day. If the bleeding is caused by another reason (a polyp, infection, myoma or another organic cause), it wonât stop even if you continue taking pills. If the bleeding persists, it seems best that you visit your gynecologist.