Im not looking for rude comments or opinions!!

Okay so im not sure how common it is to get pregnant when you are not ovulating. my boyfriend is in the military and when he came home we had sex and he did finish in me. My calander told me that it was omly 3% chance of me becoming pregnant yet we did this for a couple days. I am not on BC, yet he has dome this before and I didnt become pregnant. I am now about a week late for my period..I havent stressed about this until 2 days ago when I started not feeling well. Someone help please?