Irregular Periods on Birth Control: What Could Be the Cause?

Question
The month of may 2007 I have been on bcp for about a year,sometime i would take 2 only if i miss 1,but my question is what went wrong? My period always fall when it suppose to during the blank pills(the fourth week). My period came on the third week of my pills, that was strang! So i continue on with the pill as normal, nothing the fourth week. June come taking my pill as normal. Miss one/double up the next day not all the time but some time,3 week of my pills goes by 4th week looking for my period to come (on tues. as normal) nothing, wed, nothing thur. nothing fri. nothing sat-sun time to take new pack of pill but before i do I take aPregnacy test Its positive. Talk to me WHAT UP????

Answer
Dear Pam,

Any time there is a lapse in the regular pill taking routine, you should take extra precaution with a back-up method of contraception for one week. The BCP is approximately 97-99% effective as a contraceptive, but it is not 100% effective. And nearly every time that a pregnancy occurs while on the BCP, we find that inconsistent pill taking without using a back-up method is in the woman's history. If the body does not have the consistent level of hormones, it leaves a small window for ovulation, and thus pregnancy, to occur.

I know it is difficult to be blind-sided with something you aren't prepared for, but I am a firm believer in "everything happens for a reason." We just usually don't know what the reason is for many years and can look back and rationalize it out.

I hope this has helped you and answered your question. I wish you well.

Brenda