Hi,i noticed a thick discharge from my vagina and it was a bit itchy, itchiness was not persistent, later i saw a bloody mucus. today watery gush of blood came out so quickly. im expecting my period around the 20th and i'm on iud. please help?

STD?: It isn't possible to help on a forum like this. You need to get professional care in person, as do all with new or unexplained vaginal discharge. There are many possible causes of your symptoms, but at your age, an STD like gonorrhea or chlamydia is most likely. Don't seek treatment (e.g. at a pharmacy) without professional exam: blind treatment is often wrong and risks complications. Good luck.