New relationship advice am I paranoid or is it justified paranoia

I'm 24 and in a new relationship we have been together for 5 months. A little background on my girlfriend she came from a rough past. We met at a gas station and ended up hanging out driving around town for 6 hours we kissed and I took her home. I found out the next few days that she was still with someone but she was done with the relationship she had checked out completely. But she was still living with him I pushed a little bit it took about 10 days but she moved out we had hung out and had sex by the time she moved out. After that we were officially dating. I don't know what happened between them in those 10 days and it doesn't bug me. As I was told he was abusive I don't know for sure I wasn't there. I do know that she had cheated on him previously because she had told me herself and her reason is because well she was done with it but our relationship is the only one that moved past just an affair. So the part where I'm wondering about being paranoid is I don't know if she is going to cheat on me. She has a history of cheating but if she hadn't we wouldn't have met. Also about 3 months in to the relationship I was sitting and waiting for her to get back and she had left her phone which does not have a password and in truth I looked through it so that I could know if she was possibly cheating because of how we met it was a red flag for me but I fell for her and I'm not one to discount someone because of their past. But I had to know so I looked through some texts and found a contact with a nickname so I read and found sexually explicit conversations with this guy who was her ex who does not live in the same town. When I asked her about it and said I had went through her phone she told me that how they were talking is how they always talk. OK red flag I told her how I felt about it and she acted like it wasn't wrong but later apologized for them and says she regrets them. And the only reason she did it is because she didn't know how to be with a guy like me gr caring husband material type of guy. But NOW she was 100% commited. I don't know how women think I am naive to a point but now I'm paranoid that she will cheat on me is this paranoia justified or me being over paranoid. Just from writing this the way it sounds written it feels justified. So either way what do I do about this.

If you had developed any trust with her, then ask yourself if it's still there. Why did you just HAVE to look through her phone?She has apologised for the sextexts and by doing so she has admitted she was wrong. She did this while she was with you, regardless of why she did it..you guys were together..and while you were thinking about red flags her actions were speaking. If you don't know if she'll cheat on you, then you really have no business being with her. If she doesn't share your values then you could be in for a rough relationship. Follow your gut and not your heart...your heart will get you into trouble, your gut will keep you true, if you listen to it.

Well I guess I should say I have a few trust issues. And she's cheated before not on me yet that I know of. Most my previous relationships ended with the girlfriend cheating so I'm a bit jaded but the reason I went through her phone was well she had given me permission previously. I don't know why but I've explained that to her. She said she had to be there when I did but this was after I looked through it. I do trust her but can't shake the idea of once a cheater always a cheater. Lately she's been overly lamenting how she feels about me and it almost seems to an absurd point. I've overheard conversations with her friends one and I heard a male friend of ours ask if his girlfriend knew the story my girl told me. My girl later in that conversation I couldn't hear it all but she said I absolutely cannot find out about it. And lastly that she was going to hang out with someone I don't really know with the same male friend we share and his girlfriend but said "after all we've done won't it be weird" which his girl replied its only weird if you make it weird. So idk if that helps push this decision one way or the other I'm the type to stick it out until I have concrete proof I just can't help but feel like I need to watch my back a little.

Well I guess concrete proof is catching her red handed but again, I'll say it, if you can't trust her then what are you doing? You are still making excuses and going along with your heart, but just take a couple minutes to think about your last few words of your previous post where you state you feel you need to watch your back..it's your instinct talking..your gut.