Fiancé hiding old Snapchat - please read. Is this sketchy ?

My now fiancé and I have been dating since the end of 2018. He proposed December 2021 on our 3 year anniversary. We had a baby girl in August of last year 2021 too . Anyway in 2019 he told me he deleted his old Snapchat and made a new one. I had access to his new one, not that I ever really checked it but that was the one he would use around me and was signed into on his phone. It only had family and a male coworker on there.

Now last night I was using our laptop that we share . I went to sign into my email & saw he was signed into his. I’m not one for snooping but the very first email was a Snapchat notification. I clicked on it and noticed it was for his old account. I guess he changed the name on it yesterday. For the account he said he deleted years ago. So I go to his trash folder and sure enough there are a bunch of emails from Snapchat with the dates he logged into his old account. And he signed into it pretty often while we have been together. He did take a break from signing in for a few months in 2020 but then started again in February 2021 , then May 2021, July 2021, August 2021, September, October, December 2021, then again in February - April this year. It shows in all those months he’d sign in at least 2-3x a month. But in August 2021 (the month we had our daughter) he was signing in at least 3 times a week after I had her. I’m not sure what he was doing on there. I was able to sign in myself by sending a password reset link to the email and I didn’t find any recent Snapchats to anyone. Which leads me to believe he would delete things. I went through his memories and there were a bunch of old snapchats of him and his ex which also bothered me. Not from when we were dating of course but why would he be checking his old account that still had so many things of her ?

I confronted him and he said he didn’t know why he was logging in (lies I know). Then he said he was just looking at old memories which idk if I believe but even if that’s the case why would he be interested in seeing old videos of his ex ? Especially after I just gave birth to our daughter? Nonetheless I doubt that’s the only thing he logged in to see. It’s just too many logins to say that he only looked at his memories. I asked him why he lied about his old account and hid it from me. He said I never asked and that it wasn’t important so he didn’t say anything. But I literally did ask him multiple times & he insisted that he deleted it. This is so weird and sketchy to me but he says it was nothing. That I’m overreacting. I honestly want him gone . He lied or omitted the truth which is the same thing to me. Idk what he was doing on there and I know he’ll never tell me the truth. The only reason I know that account existed still was because I found it. Not because he was honest so I know he won’t ever tell me the truth of what he was doing on there. Is this weird , am I overreacting ? What do you guys think?