please read!!

hello lovelies this has to do with birth control but im a bit unsure if its still the right topic group but im in need of help because im litterally racking my brain. i have been on implanon for just over 2 months now i am really concerned that im actually experiencing a miscarriage, when i had this inserted i was told that it was 99% effective and it was so unlikely i would fall pregnant but im believing otherwise. since being on the implanon me and my boyfriend have had unprotected sex not often as i have been experiencing on and off spotting which i expected at first but the last 2 weeks have been a whole different story. i spotted for a few days (sorry if this is TMI) i passed more of brownish spotting but then a couple days went past and it began to be heavy which i didnt think weirdly of just thought it was my actual period so i didnt think of it but i went to gym with my boyfriend and starting experiencing awful pain and sickness to the point i had to go home but the pain only lasted a few hours till i started passing large bloodclots and my period becoming lighter over the days i was very clotty for about a week and then started passing lots of tissue like clots and that went on for a few days until it just turned to me passing very brown sometimes almost black thick discharge like spotting and now stopped altogether. my emotions have changed aswell im riddled with almost like guilt and im very depressed and just wanting to keep to myself. im unsure if to go to a doctor i need advice, help opinions please this is the first time ive ever experienced something like this :/ thanks in advance