Nobody knows my boyfriend has a gf

So me and my boyfriend have know each other over a year and be seeing each other for about 3 months and the rest we were oficial.

I feel like he’s hiding me or something or like embarrassed of me because we only have our Instagram profile photo of us with each other and he has never puts me on any of his social media like Snapchat or Instagram story sonothing. Just makes me really insecure and like curious to why he doesn’t want to like have me on his Instagram and show me off like everyone else does with their partner.
Whenever I said to him like why don’t you he just says oh well you never let me take a photo but he has never asked lol and the only reason he has me in his pp is because I asked...
also I look very young in the photo on his profile picture and my fear is that he might just be telling people in his sister or something lol
Is it because he is talking to other girls? And doesn’t want them to know??
He goes away to Amsterdam and then kinda places a lot and sees his friends every weekend ?? I’m so upset like am I just overthinking
No nasty comments pleas