Hi I Have Had Implanon Continuous For Nearly 9 Years

Hi I have had implanon continuous for nearly 9 years I'm on the 3rd one now. I don't usually have a monthly bleed but sometimes have a bit of blood loss every few months just for a day or so, but about 5 weeks ago I started losing brown discharge sometimes thick sometimes watery but the smell is foul it's not a fishy smell just very strong wierd smell and last week I had bright red blood and about 6 colts passed the biggest was same size as a tea spoon then I have had brown discharge ever since but I am starting to get really worried. Thanks