I have never used BC and was recently prescribed Microgestin FE 1/20 by my doctor, but I am not sure when to start. My doctor said I could start taking the active pills at anytime and take the FE pills during the period, yet the instructions indicate that I should start taking active pills during my period.

What my doctor told me makes sense but is it wrong? Why should I start taking active pills DURING my period and not after?