I've been on sprintec birth control pills since April 2016. I've never missed a pill and have never taken a pill more than 4 hours late. My last period was February 6th. I had intercourse on the 17th but the condom broke. I took plan b 30 minutes afterwards as a precaution. I got my period on march 6th as expected. It was normal the first day then became light. Not light enough to be considered spotting but lighter than my normal periods. I did begin taking ibuprofen on the 6th for wisdom teeth pain and have been taking about 2400 mg a day. One 600 mg tablet every 3-4 hours is what's prescribed to me. Could the ibuprofen be causing my period to be weird or could I be experincing pregnancy bleeding?