I had a 4 week period after I got mine in now they are a tad heavy then normal but I can cope with that. Maybe with you not having one since September it could be normal I know it's normal to spot once in a while if it doesn't stop see your DR but I think it will stop soon.
Before I Got Pregnant With My Daughter My Period Wouldn't Come But 2-3 Times A Year At Random Times Lasting 7days Or So. Got My IUD Placed At My 6 Week Postpartum Appointment In September, I Had My First Period Since IUD Been Placed 2 Weeks Ago And I'm Still Bleeding, Heavier In The Morning To Afternoon Time And Very Light At Nights
Hmmm That's Something I Never Thought About But I'll Wait To See If It Stops By The End If The Month