Pregnancy while using dronis 20.

Hello doctor! My friend had undergone protected intercourse (partner has used condom) on 19th day of the pill(dronis 20)in March 2022.She has been using dronis 20 since 2 months (Jan 2022) for PCOD and irregular periods treatment and it is advised to use for 6 months.As usual and as advised by the doctor she has started the fresh pack of dronis 20 from 5th day of her periods and upon completion of the pack she will get my periods within 3 days after the completion of the pack.This time during the month of March 2022 as she have undergone protected intercourse while using the pill, she much worried of any possibilities of getting pregnant.Can you please advise as don't want it to happen.Also advise on if her periods come as usual and any chance of pregnancy after periods? Kindly help with the advice. She is taking the pill regularly at same time before going to bed. her pack got completed on 24th of this month ,will you let me know when can expect periods dis month.Warm thanks & regards