<human>: Provide a brief overview of the text.

withing the past few days, i had received information from an old friend, that my current GF had cheated on me with another much older friend a few months ago.l This information was, shaky, at best, but irregardless I took seriously and wanted to do a little digging. Well last night, while my S/O was sleeping, i went through her text messages and found some mildly incriminating information. There were no blatant discussions about previous events, nor any talk of betrayal or hatred of me. there was however quite a few "i love you" messages here and there for the past few weeks. I regret now not being able to check the dates and to see how far back it went, but considering how much she texts others, it couldn't have been more than a month (while the event as told to me happened much earlier this year) I have made absolutely no moves, no hints, no nothing. last time something like this happened i flew off the handle (Words were said, absolutely no striking or hitting of absolutely any kind) and this time i want a much more calm and collected approach. He will be coming back from the military in a few weeks and will be staying for a month, that's when i will be doing most of my "sleuthing" and digging. Again, as slow as i can take it, for i have no true concrete evidence so i don't want this blowing up in my face. She has exhibited none of the "signs of cheating" that many will show, as a person she hasn't changed much recently, nor had she started any changes if she indeed had been physical back in the past. I hope this is coherent, and i hope i catch all spelling and grammar errors before i submit. i'm currently shaking with rage ATM because i no longer have to keep up a facade since i'm at work (US security guard post). Any help comments or advice greatly appreciated, i will be on for the next 7 hours.
<bot>: Possible cheating Gf, but very conflicted as many signs don't quite add up. General advice or suggestions greatly appreciated.