GUYS...is he a Dog? Is he on drugs or am I just over-reacting?

I have been seeing my man for almost a year. He just got out of a marriage and dated 2 other girls before me. We both have kids from other relaionships. He seems to really care about me, but once every 3 months he will just up and disappear for a few days, no contact w/me. He is a good father and a good man to me, not abusive or a drinker. He used to party alot when he was younger as did I. since the last time he disappeared he explained to me he went out with his friends and when he drinks he gets a lil carried away i told him maybe he needs to be single 4 a while and he said he did NOT want that life. Ive never suspected another girl, he's always been faithful. since then hes introduced me to his mom fam and KIDS which is a BIG DEAL for him, he has told me i am 2 good to be tru, i do alot for him, he seemed happy i was happy we never fight argue or have doubts. last week he didnt call me for 5 days today is the 6th, ive texted and called he wont call me back. What does this mean?