Hi, Have Had Black/brown Stringy Discharge For About 6months, Crampy

Hi, have had black/brown stringy discharge for about 6months, crampy tummy, oily bowel movements on occasion(suffer ibs) discharge at times is watery, or blood after number 2 toilet, have had cin 2 10 years ago , been on micrgynon for 20 years although no docter has suggested a change, break or expressed concern, I sometimes bleed after intimacy , nurse has suggested swaps, and bloods,for hormones and tumour markers,advise please,bit scared