Hi.. i started using lo loestrine fe 6 months ago is it normal to have my period in the third week of the pack ? i always get it the forth week

Breakthrough bleed: Unscheduled bleeding is a common side effect of any birth control method but very common on low dose pills. It usually corrects itself in a few days or over a couple of cycles. If not then you will need to schedule a visit to discuss changing brands or changing methods and make sure nothing else is wrong. Other than being annoying for you it is not harmful.