In July my period started on the 9th. I had unprotected sex on the 25th, but he did not ejaculate inside me. I was worried about precum though. I took Plan B One Step on the 27th. I did not feel any symptoms right on, but after a few days I felt a little nauseous and dizzy and my boobs hurt. I finally started what I think wasn't period 3 days late on August 9th. It only last about 3-4 days. Could I be pregnant? Was that my period?