is he going to cheat on me?

my husband had a new job 2mths ago, they paid him $3 less than his old job, and promises to pay him $2 more than his old job after 3mths of working there. he used to always complain to me that if they dont pay him more than what he needs, hes gonna leave that place. or go talk to them about it. he said hes so broke everytime cause he gets paid so little. right now, he changed, and says if they dont pay him, he doesnt mind. he will still work there and doesnt care if hes always broke all the time w that lil pay. before he told me this, ive been seeing him smiling while reading txt messages w someone, hed just scroll back up and reread the messages. but idk who its from, hed turn his phone away from me, like to the side, or face it downwards so that i wont see what hes doing. hes very secretive w his phone and bank, when he wasnt before. and he no longer call or txt me on his breaks, when he used to all the time. after working at this place, he stopped.