Suggest Medication For Pain In Back,stomach And Headaches

On March 12 my girlfriend and I had sex and the condum broke but before ejaculation was reached. Instead of waitin for the period she took Next Choice the day after. Second pill was taken da next morning exactly 12 hrs after. later that day she took a preg test and it was shown as negative. for the past 3 days she has been complaining about pain in stomach, back and constant headaches. Starting March 15 the pain spread through out her body. What could be causing the pain if the test was shown negative?