My period ended last wednesday. on thursday i had unprotected sex. today (4 days later) im having brown/pink thick discharge in my underwear.

Some thoughts...: Many women have vaginal discharge, but some types of discharge are not normal. A woman may see normal changes in discharge before or after her period. Changes in discharge that may be an infection: a bad odor; vaginal itching or swelling; a green, yellow, or gray colored discharge; discharge looking foamy or like cottage cheese, etc. A doctor can check, if symptoms persist, recur or are worrisome.