What Causes Vaginal Discharge After Sexual Intercourse?

Hi. I have had a vaginal discharge for more than 4 weeks now. It started after sexual intercourse with my husband, and never stopped from there on. I skipped one of my birth control pills about a week before this happened, but took both the next morning. I went to my GP last week Monday, and a sonar was taken. No signs of cysts, but they did pick up that i had some fluid, and said that it could be a possible infection. I was given a single dose of Zithromax, Cyklokapron (3, twice a day), for 5 days, and Levofloxacin-Winthrop 500 for 7 days (which i used the last of last night). My concern is that i still have a discharge. It's not as bad as it was, but it's there. And i have pain in my lower abdomen. Could you please give me some advice. Thank You