Period and birth control

In September of 2015 I got an implant of birth control due to a 6 week long period. Since I received my implant my period hasn't stopped. I started on the pill version too so maybe that might help. I am severely anemic and get cramps and migraines worse than normal. I am 14 and I have a vaginal sono scheduled for the 20th to see what's up. If anyone knows what could be happening, please help!!