Hi thanks for your question
with abnormal bleeding is normal after IUCD insertion.
However delayed in cycle usually don't occur with IUCD.
It could be due to change in the pattern of your cycle which usually occur when women approach their menupause.The other reason could be pregnancy
and if the delay is more than a week I would like to advice you to go for home pregnancy test to know, if pregnancy is the cause of delayed periods, as pregnancy do occur with IUCD in uterus
of stomach could be due to hyper acidity which can treated with antacids and tab. pantoprazole
Hope this answer your answer