Thanks for posting on HCM,
The only condition that I am seeing that could explain your presentation is pregnancy
. You could have gotten pregnant before insertion of the copper IUD or after insertion (which occurs in very rare situations). Presence of IUD with pregnancy can induce a miscarriage
. So a miscarriage can explain the the bunch of fiber mixed with white mucous. Even though you should have experienced this mixed with blood, I can hardly explain that unless it is a miscarriage.
Another possibility is infection or STD
. You need to get screened for STDs and be treated if that be the case.
Also see a gynobs for further evaluation.
Hope this helps