Could i be pregnant help!!!?

my and my boyfriend have been having we always use a condom and he pulls out. he left for basic training 3 weeks ago soo i havent been having and my period hasnt come. Ive been really stressed out that hes gone and i just got a new job and ive been working really early soo ive been tired but only the days ive worked. I only had cramps for like 2 days and i was suppose to get my period 5 days ago. my period isnt regular yet only thee past 4 months it has been and i know if i have and then stop for a while like last year i skip my period. Could i be pregnant even tho i havent have any signs like other people have?