Want to snoop on bf phone again.. help

We've been together 3 years. Before I even start I don't want to hear anything about (trust) because I KNOW. I've been on my boyfriends phone before and I've found stuff on accident and since then is snoop again and find more shit that I would bring up to him. I KNIW ITS WRONGGG. I'm 30 weeks pregnant and I haven't looked on his phone in AWHILE BECAUSE I do trust him but my past relationship has affected me a lot and I know I shouldn't let it get in the way of this relationship. He's asleep rn and my insides just wants to go threw his phone but I'm telling myself NO because it's fucked up. Am I the only one who goes threw this? How do I cope with this? I don't want to feel the "erge" to look threw his phone it's not right.. plus he's just been acting strange... doesn't kiss me or starts things anymore we used to have sex all the time like wtf.... I wish a guy could give me advice but I know he wouldn't cheat 1000% I'm just "insecure" I guess?? Hormones?? Idk...