Welcome to HCM,
You should check the string to check that whether the Copper-T is in its position or not.
Copper-T can cause irregular periods
and spotting between periods
up to first 6 months after insertion.
Though it can provide contraception
for long duration, but doesn't provide protection from STDs.
You can get it examined by a Gynecologist, and if creating problem regularly, can get it removed and to use condom during sex.
Thanks for your trust in Healthcaremagic and posting your query.
Hope you found my response to your query informative and helpful.
With good wishes,
Dr.Chandra Shekhar Sharma