Am I wrong?

So a little back story first...

I was in a horrible abusive relationship for 7 years, he would also sext other women (I got my suspicions and used to check his phone)

Fast forward a few years and I’m in a new relationship with a guy I met in work.. We’re together 1 year 7 months.. I’m currently 14 weeks pregnant with our first child..

Before getting pregnant I was a smoker and so was he, both cigarettes and the occasional joint.. After talking about trying for a baby I said I’d pack in the occasional joint and my OH said he would too, since finding out I’m pregnant I’ve also given up cigarettes..

Again I had my suspicions that my OH hasn’t given up smoking weed so I went through his phone and found messages of him asking an old work colleague for his fix..

I’ve brought this up a few times but he just brushes it off.. He’s recently lost his job and has lied to me about this also which sent me into a panic because we were relying on his income due to me being certified off by my GP for hyperemesis..

Am I wrong for going through his phone? He says he’s going to quit both before baby is born but that’s 6 months from now and I don’t think I can manage the lies anymore...

Also other than this he’s been great throughout everything, he does everything around the house, cooks and cleans.. He smokes outside too because I can’t stand the smell..

Should I stop being crazy or am I right to have to go through his phone?

***EDIT***

I DO WORK I’m currently under doctors orders not to be in work due to having hyperemesis (severe morning sickness) a debilitating condition..