I think my husband is cheating through Snapchat

I went on my husbands Snapchat on his phone and I saw that there were many chats with various females who looked very promiscuous. I only opened a couple and they said hi from his end. I didn’t get a chance to see or read anything else as he wanted his phone back so I logged on his Snapchat from my phone and could not see any of those chats, only conversations with his work friends. he doesn’t know that I was on his phone on his Snapchat, So why were there many chats on his phone but when I logged on my phone they weren’t there? I’m really confused and I don’t know how to use Snapchat. Someone please help because I’m really worried.

Before anyone comes at me for sneaking through his phone, I have my reasons which I don’t need to explain. I’m simply asking why there were chats on his phone and none when I logged on my phone.