Hard time with my boyfriend

im going through a hard time with my relationship with my boyfriend because he is always going out with his friends every friaday and saturday and gets home like at 6 in the morning and always leaves me home with my two little girls without getting us out anywhere and we are always fighting because of that but i think he is cheating on me because he never answer hes phone when i 'am calling him and i don't know what to think now please tell me what can i do............................ :'(