My boyfriend is being weird with me?

my boyfriend of nearly 2 years is being off with me, and i dont know why, we had on friday, cause it was his birthday on that day,then the day after i went to town with my bestfriend to get some baby clothes for our child without asking him, and he started shouting at me, saying that i should of told him to come with me, then he wouldnt text me all day, then he finally text me, saying 'ill text you in a bit im playing footie x' he sent me that at 4:50, and i text him at 9:00pm saying have you finnished yet? and he hasnt replied, i text him about 5 times, and he hasnt text back, i dont know why hes doing this to me, im 14 by the way, he stays at my house sometimes, as we have a 15 month old baby boy together, my boyfriend is muslim, and hes 16, we are engaged, and when i turn 18 we are going to get married, his parents are fine with it, as i plan on taking up their religion, and please no nasty comments, as i know you will all think im a tart for having in the first place, i just want advice, thanks.