Long periods with Mirena

Hey ladies! So I've had my Mirena for pry 2 1/2 years. My period never went away but it was shorter and really light. It came at the exact same time every month. Well in July I had to have a biopsy done on my cervix due to HPV which came back fine but ever since then my periods have become really long lasting up to two weeks but still very light. What I'm wondering is if anyone who has a Mirena for a little while  has strange periods like me or that it could be from the biopsy.