It can remain in place for up to 10-12 years as an effective method of Birth Control
Leaving the copper IUD in longer than you are meant to is not dangerous and will not cause illness.
A Multiload IUD is a copper IUD.
The ParaGard IUD is T shaped and it contains copper.
If by copper you mean a copper IUD, it depends on the brand. Copper IUD's can normally be left in the uterus from 5-10 years depending on the brand. Obviously an IUD can be removed earlier if you want to try to conceive or switch to another birth control method.
Allergy to copper or Wilson's disease are contraindications to the copper IUD that don't apply to the levonorgestrel IUD. In addition, severe anemia is a contraindication for the copper IUD, but may be an indication for the levonorgestrel IUD, particularly if the anemia is exacerbated by heavy periods.
If you leave the copper IUD in too long, there are no potential health problems. If you leave a hormonal IUD like Mirena in too long, you may not be protected against pregnancy, but there are no other risks.
No, Mirena is a plastic IUD containing progestin. The copper IUD on the market in the US is Paragard.
Fertility returns to your baseline after removal of the IUD. Whether it's easy to get pregnant after removal depends on your fertility, not the IUD.
If you leave the copper IUD in too long, there are no potential health problems. If you leave a hormonal IUD like Mirena in too long, you may not be protected against pregnancy, but there are no other risks.
That is not how an IUD works. What an IUD do is to stop an egg from attaching to the inside of the uterus. It had no effect on the sperm. But no, it shouldn't hurt.
A copper IUD will not delay your period. The same things can cause a delayed period in women with or without the copper IUD. These include pregnancy and hormonal fluctuations.
The copper IUD does not change pigmentation. If you have an excess of copper (WIlson's disease), the disease could cause change in pigmentation, and the IUD could worsen that. Talk with your health care provider about your particular situation.