Copper coil fitted 31/1/19. current period is 11 days long - started 8/4/19. last period 12th march lasted 7 days. just wondering if this is normal?

IUD Bleeding?: An IUD can be forced into the cervical canal by uterine contractions, causing persistent bleeding, but since no contraceptive is 100%, check for pregnancy with a serum HCG test, as an IUD in the cervical canal is not as effective a contraceptive.

Sounds like it!: One of the known side effects of copper IUDs are heavier periods. As long as you aren't having unusual pain or bleeding so heavily that you are getting lightheaded, etc., I would chalk this up to the IUD and give it a few months. Your body may settle down after a few months of getting used to its new normal. If it doesn't, and you don't like the new normal, you can always have it pulled!