Can Delay In Periods After Having Implanon Cause Weight Gain And Brown Discharge?

Hi im just abit worried i am on my 2nd implanon and have not had a period in nearly 2 years , this weekend i have started to notice like brown blood coming out when i go to the toilet i notice it and when i wipe myself i also noticed a bit of a clot , just a bit worried ? I have also noticed rapid weight gain but dont feel like i am eating alot to do this