Worried that i might have an infection..?

I have had my periods for over a year now :/ been to the doctors loads, had an examination, had swabs and urinal tests, but theres nothing :/.. ive recently just done oral and havent had sex properly, ive recently taken a chlaymidia test so waiting for results..but when i wear a tampon theres like a slimy substance on it, and sometimes a yellowy brown patch on it,same on a pad but no smell. so im wondering if its an infection? :S but the doctors havent said anything about it, I have no itchyness or any symptons :S ..ive got a sore throat and i got antibiotics but since ive taken these, theres a lot of discharge, im very worried :(