gud morning.. i understand ur anxiety for ur child .but at the very outset i would like to inform u that during menarche ie starting of the menses ,these disturbances r common in most of the girls..i feel its been may b nearly 4-5 mths only since ur child got the first menses.. so for atleast 1 yr or even 2 yrs u need not b afraid of these sort of irregular periods as these are the consequence of anxiety or irregular diet or improper hormonal balance.. skin inf is one of the side effects of tab modus or any hormones ,so nothing to worry.. as per my opinion i feel u can better stop the tablets and just give diet full of iron content like green leafs and then follow up for 1 mth ..if everything is ok ,then nothing to worry..sometimes even family history is also there.. so better stop the tabs and wait with good diet for 1 or 2 mths ..