Hi I Had Unprotected Sex On The 18th Of Feb

Hi
I had unprotected sex on the 18th of Feb and took an unwanted 72 in 4hours and took another pill after a day. My last periods were on the 4th Feb. After taking the pill I had slight spotting after 7days and I have been having cramps since then. Recently I have had brownish discharge. My urine test shows a negative but I had taken the test in the night. Kindly provide with your opinion