EXTREMELY LONG PERIODS. HAALP?

Keida • 19 Year's Young, Animal Behaviour & Wildlife Conservation Student. Diabetic since 2014, Whacked out periods, On Implant.
So I have VERY long periods. Like I was diagnosed in December 2014 with Type 1 diabetes & for 7 months after that I had no periods what so ever. Then they came back but very irregular & now I have semi-regular but very long periods :S like they'll last 3+ weeks
Obviously this hinders certain 'activities' but it's also very frustrating & I don't think good for my health :( it's happened like this pretty much since my periods started up again and I don't know if my method of birth control {implant} has anything to do with it or if it's to do with my diabetes :S 
Does anyone have any advice or should I approach the doctors about this? 😭