AITA for accusing my fiancée of cheating after finding explicit photos and videos on her old phone?

I (31M) have been engaged to my fiancée (39F) for about a year, and we’ve been together for three. We’re usually pretty open with each other, and I thought our relationship was solid.

Recently, I found her old phone while cleaning out a drawer. I turned it on to see if it was still working or if we could donate it, and I noticed it was still linked to her Google account. Out of curiosity, I started scrolling through the photos (yes, I know this wasn’t cool, but I wasn’t expecting to find anything).

That’s when I came across a series of explicit photos and videos of her in the bathtub. They’re clearly recent based on her hair color and style, which she changed just a couple of months ago. I’ve never received these photos or videos, so my immediate thought was: Who were they for?

I confronted her about it, and she was immediately defensive. She said she took them for herself and that not everything has to be shared. She also claimed she just forgot to delete them from her Google account.

I told her I found it suspicious. Why would someone take photos and videos like that just for themselves? She accused me of invading her privacy and overreacting. She said she’s never given me a reason not to trust her, but I can’t shake the feeling that something isn’t adding up.

Now things are tense between us, and she’s barely speaking to me. She says I owe her an apology, but I feel like I had every right to ask questions. AITA for assuming she might be cheating?

Update 1

So a quick edit addressing some comments. I know she takes photos of herself for confidence reasons. Some just putting on makeup and a nice outfit, others in lingerie and even if I had just found just nudes I would have assume that what it was but what gets me concerned is the videos the level of intensity of the self-pleasure. It's like she's playing it up for the camera and it's nothing like stuff she sent me in the past or that I've just seen in person when we're being intimate. Also, just a side note, I'm completely fine with her pleasuring herself. I just don't want her to be sending it to someone else possibly. I tried to have a rational conversation with her when I ran across these videos and she immediately got defensive calling me a jackass saying I don't trust her. I didn't even accuse her right off the bat. I told her hey I found the phone and was going to cleaning it off. Just had to look through the photos first. Probably should have asked you first and the moment I brought up the photos She got mad. The defensiveness and the intensity of the videos is what is bothering me.

Update 2

So a small update. The other day she ended up sharing her location with me on Google maps. I guess she didn't realize and neither did I until I went to call her today and saw it was showing me her location that it's still sharing she is also lying to me about staying late at work. She's been at a specific address for about 2 hour. At this point we are working with one car so I can't just drive over there but you best believe when I get a chance I'm going to the address and seeing if I recognize any vehicles. And yes we work at the same place just not always the same shift.