First pregnancy and marriage

I’m (F23) 32 weeks pregnant and it’s been the hardest mental battle I’ve ever faced on top of getting engaged while always being terrified and uninterested in marriage until I met my (now fiancé.) We met about a year ago and he’s literally been the man I’ve wanted. He takes care of me, he’s a hard-worker and knows how to keep me satisfied, etc. In the beginning, we both established that we wouldn’t let each other go through our phones, because of past instances where it has spiraled out of control on our partners end and ours. So we just concluded it be best to just not mess with it, basically. I feel like since our relationship has gotten more serious with me getting pregnant and us planning to get married, I’ve had serious doubts and insecurities surface for me and all of the times I’ve brought it up to my fiancé, he blatantly refuses to make an exception to our no-phone-check rule. And I’m sure that my pregnancy hormones have a play into my doubts and insecurities because I do feel like they’ve intensified since then. We live together and he never seems to miss a beat, but him standing his ground and not giving me that type of transparency for my security to fully trust him, and I’ve even communicated that to him. Here lately, I’ve been getting really depressive episodes like I’m having right now where I just do not want to get out of bed and face the day. I’m still trying to decipher if it’s just pregnancy hormones or if I’m actually sensing he may be doing things on his phone behind my back because I know how girls/women are with baby daddies and I’ve seen so many stories of homewreckers and my worst fear is to have all of this with one person while they just lie and do all of this horrible stuff behind someone’s back that they “love” I feel like we’re usually pretty good at communicating when something is bothering us, but at this point, I feel like it’s pointless to keep bringing my insecurities up if nothing is really done to prove them to be wrong.