What Causes Pain And Burn In Vagina With Yellowish White Discharge?

For the past 3 weeks I ve been having pregnancy symptoms and I ve taken a test but it came up negative, now my vaginal entrance is really pinkish/redish it hurts really bad to the point where it hurts for anything to touch it.its a severe burning painful feeling, along with yellowish white discharge. I ve had this for about a week...What could be causing this and what can I do to fix it and make it feel better? please help I ve never experience anything like this.