i have the contraceptive implant which i know can cause irregular bleeding , however latelty i ve been getting a mucus like bleed. it s happened twice and both times have been after i ve had sex. i m 17 and have been with my boyfriend for over a year. he s the only person i ve slep with, however he s had sex with another girl. could this bleed be due to an sti? if so, why havent the symptoms shown up before this? i ve also had slight stinging when we ve had sex, but that was only the first time i bled. the first time i bled was also just after coming off of my period, in which i suffered from a lot of discomfort and itching. could this just be thrush?