This goes back a long while now but I had implanon, I know it's not the same but it affected my mood. I was spotting (bleeding) non stop I gave it 3 months before having to go seperate doctors asking to remove it. It cost 200 dollars at the time and the first doctor who was a woman too said stick it out for the 3 years and I remember crying. I can't say my exact emotions being long ago but they were negative and strong. I recall looking at so many forums to make and because i wasn't alone in the matter.

Only way of finding out is getting it removed unfortunately, it wouldn't be hard to notice the changes if it was affecting your mood especially when you still remember how you were beforehand