What should i do?? he disappeared!!?

i was talking to this guy for 2 months REALLY talking to him. we were pretty much together just not using the title bf/gf. we had our share of little arguments here and there but nothing i thought was that serious. then all the sudden he just ignores me. wont answer my texts or ims. its been 3 days. ive texted him like 4-5 times but 3 of those times were b4 i realized what he was doin. so idk what to do. i rly rly like him a lot but i dont want to be the stage 5 stalker. how long should i give him space? i ume i did something to piss him off but i have NO idea what besides hanging up on him the last time we talked. and i was kidding when i did it, it was a joke. he added a new girl on facebook so idk wat to think. any advice??