דימום בזמן לקיחת גלולות

I'm using Mercilon pills for over a year. In the last two month I'm bleeding as if its the begining of my period while I'm still using the pills - in the middle of the package. I wanted to know if it's O.K and why does it happends? Thank you, Sharon. (I'm sorry but I couldn't write in hebrew from this computer)

Itramenstural bleeding is commoc and can becaused from a number of reassons. An ultrasonography may help to find the reason the solution is easy.