My Last Period Started On December 21 And Finished On

My last period started on December 21 and finished on December 25, which was a few days early, but not by many. Yesterday, January 7, I noticed I was beginning to bleed again, but it wasn't heavy. I am not trying to get pregnant, but my husband and I often have unprotected sex and stick with the "pull out" method. Is pregnancy a possibility? What should I do now?