Have Mirena Coil. Brown Discharge, Fleshy Bits. Have PMS. Negative For STI. Help

I had the implanon implant removed a year ago an had side effects so got it removed an then had merina inserted coil straight away I started to hav bad thrush infection so doctor removed it an offered me the pill about 3 months ago I took the pill only around a month an decided to stop using it an give my body a break periods hav returned to normal but ive notice between period im getting a brown discharge with pink fleshy stringy bits thru it an quite concerned plus ive hav severe pms to the extent that ive went to try any vitamins I can to relieve my symtoms im wondering is maybe my hormones all out of sink an the fleshy bits maybe a build up of mucus due to contraceptive s also been having pelviv pain an hav been tested for sti, s an all negitive