Could you get pregnant if your NOT ovuating ?

Patient: Hello, My main question is can you get pregnant when your NOT ovuating or its not one of your most fertal days, but i have a few others as you read on? Me and my boyfriend want to try for a baby but hes in the military so hes only home for so long for the holidays!! I have this app. on my phone and its call “Woman Log” and it keeps trake of when im going to start my next peirod (not always right) and when im most fertal during the month; this month in Dec. it said that i was most fertal from the 13th through the 20th, i had sex the 21st and the 22nd an both times he ejaculated in me and we are going to keep trying, could i be pregnant already TODAYS DATE 12.24.11? The log saids i should start my period on the 31st so should i watch out for it come, and while doing so if i am possibly pregnant how would my up an comming period days be, what should i expect?! THANK YOU so much for reading this and il be waiting for answers!