welcome to Health care magic.
1.It can be post operative site inflammation / infection, uterine and ovarian pathology, physical
stress on the post operative site.
2.To come to conclusion one has to examine the post operative site, and an
ultrasound abdomen pelvis to make sure the IUD is in place, presence and absence of any ovarian pathology.
3.Since its only 10 months post operative, you minimise giving stress on the stitch area.
4.To evaluate the things you have to get the minimal investigations mentioned.
5.Yes, you have to worry,because its better to evaluate early that wait till it gets worst / complicated.
Hope it helps you. Wish you a good health.
Anything to ask ? do not hesitate. Thank you.