<human>: I was cleaning the bedroom I share with my gf. On the side of her bed, I found the top corner of a condom wrapper. It was small enough I had to examine it to be sure it was from a condom wrapper, but some tiny print gave it a way. I've never used this brand. It's not mine. 

My mind was rushing. I've never had a reason not to trust her. We've been talking a lot and even planning for marriage. Out of everyone I've ever been with, she's the least likely to cheat on me. The only things I can possibly think of is that maybe somehow either her or I dragged it in on our feet or, more likely, our dog may have found it and brought it in. 

I have no idea how to handle this. I want to ask her about it, but I fear that, even if she denies it, I won't believe her. If you have advice as to how I should handle this, please share! Thank you!

Can you condense the text into three sentences or less?
<bot>: Found a condom wrapper on my g/fs side of the bed. She's very trustworthy. Could she be cheating?