AIO when I found out that my boyfriend traveled to see his ex 15 days before I gave birth to our first child?

Sorry if this is scattered and more like a rant I am DISTRAUGHT and livid and I don’t know who to turn to.

I 29f just found some pictures in my boyfriend 35m phone dated 15 days before me giving birth to our first child.

I went into the phone to get pictures from when our second child was born. I got lost in all the family photos he had and pictures of our kids I’ve never seen. I loved them and loved that he took them until… I got to a photo of his ex in a bathing suit on her stomach suntaining. The next picture was of him, in beach attire in a hotel room. I’m the picture you can see a purse and women’s items.

I asked him about them. If my texts are accurate in my phone (which how could they not be) I knew he was going out of town but I was o my told he was going to California. He DID NOT tell me he was “stopping by in Florida to say hi” before coming home.

I am so damn sad. He told me that I am overreacting. He went to see her mom and her to handle “financial matters” or “handle business” in his words and that it was nothing like that. For reference they were together for like 16 years on and off and they did have an in depth life together before me.

Said he went for a day but the pictures were dated on multiple different days.

Says they live in Florida so why would he be in a hotel room surrounded by women’s things?

I look back at our texts from those days and I’m 9 months pregnant miserable, missing him and telling him so and he would just stop talking to me at 11 and then would text me the next day telling me was “KO”. Whole time he was with her.

In his words this was years ago. This is old. I’m sorry but this is NEWS TO ME.

So am i overreacting about this new information?

Just to mention for the first half of the conversation he was smiling and making light of the whole that and was actively making me feel crazy. He said it was nothing like that but based on previous experiences I’ve had with him and this ex, idk anymore.