Implant Period

I NEED to know if this is normal. I have the arm implant form of birth control. I have a period MAYBE every 3/4 months, but every month I might not bleed but I have every other symptom of a period. I’m led to believe that’s normal.. but! When I do have a period it is tragic. It smells, it’s slow (as in lasts forever), I don’t bleed heavy. It’s like my whole pH balance is efffed. Do other women have this problem??