what would you do in my place with your boyfriend?

last night at around 10 o'clock me and my boyfriend have a huge argument we end up swearing at each other, then i went to have a shower and we didn't speak again, i went to bed at around 11 o'clock looking over our 8 months old son which was sleeping at the time, later at around midnight when my son woke up i went to the living room and my boyfriend was not there, his friend came by and they went together in his car, he didn't tell me anything that he was going out i tried calling him and his phone was off, i called his friend's mobile he never picked it up, when i retry on my boyfriend's phone it rangs like four times and then i just hear he phone shut in my ear and his phone was switched off again, i locked the bedroon door where me and our son was sleeping ,i texted him and tell him to sleep in his brother's room which was not occupied, i heard him playing with the door handle of the room and when i looked at my time it was 2.15 am in the mornig, that means he was out all this time without me knowing where he was, he could have been cheating on me!!! because he did it once in the past but i forgave him because i did the same to him and we were working on our relationship, or i don't know, things were so great but i feel so bad right now i don't know what to do, i'm thinking about leaving his house and go back to my home with my son, never talk to him again and break up with him. this morning when we was awake he never talked to me at least not telling me where he was, nothing !!!!... not a single word..he went to work and i didn't say anything too..... waht would you guys have done in my place??? would you go back to his house and ask him question?? would you leave him?? give him another chance?? my day has started so bad and i feel so sad , i told his mum about it, i don't know if i did the right thing by telling her but i live at his place and he has no right to treat me like this even if we have an argument, i'm soo mad..please i need advice thank u!!