Taken Postinor 2 twice in 1 week, should I take another ?

Hi, my period finished on Tuesday 14th, I had unprotected sex same night. I then took Postinor 2 the next day in the evening. Had unprotected sex again on Thursday 16th at about 1am and boyfriend came inside me. I took another Postinor 2 on Saturday morning. Saturday evening I had unprotected sex again and he came inside me too. Please can I get pregnant ? And should I take the 3rd set of Postinor 2? Urgent response please. Thanks a lot