cheating or paranoid?

my boyfriend and I had a miscarriage last year and took me a few months to get over where we didn't try. we then began trying again and then recently he just turned around out of the blue and said he doesn't want a baby with me any more. I don't know if I'm being paranoid that he's cheating, because he works 12 hour days (he's security) and is often doing overtime and is so secretive of his phone which he never used to be. also he gets paid more then I do but never has any money, but has nothing to show for what he has bought. am I being Crazy?