Hi. My Last Cycle Started On 16th June, Next One

Hi. My last cycle started on 16th june, next one should be 14th July, today. i took postinor 2 on fri, 10th July. i had unprotected sex yesterday(monday) 13th July and he is not sure if he came inside me. Can i take another dosage of postinor 2 or I'm I safe based on safe period theory? I really need to be sure i wont get pregnant now. Also, Im having a bit of abdominal cramps similar to my normal menstrual cramps.