Hello and Welcome to ‘Ask A Doctor’ service.
I have reviewed your query and here is my advice.
You didn't mention what was your
ultrasound finding. If IUCD is within
uterus, you may not need to worry.
The possible possible causes of your pain are:
Pelvic infection which is more common after IUCD insertion.
Side effect of IUCD.
Rarely IUCD may injure the uterine wall.
So, if pain persists better to consult your gynecologist once, get examined if needed repeat the ultrasound.
With this work up the possible cause of your problem can be identified and treatment can be taken accordingly.
Hope I have answered your query.
Let me know if I can assist you further.