Hey, sorry, if I saw this thread earlier, i wouldve responded..
It's most likely the implanon. I bled really light for some months, and sometimes I wouldnt bleed for months. It mucks up your whole body.
As for the dull aches, implanon is there to mimick pregnancy so you can have pregnancy symptoms or even af pains when af isnt there, just coz the body is confused..
I had mine in for just over a year. Weird times.