He doesn't post about me EVER.

So my boyfriend and I have been together for a year and one month today. In the whole time we've been dating hes not posted a single thing about me on any of his social media, only Facebook to say we're together (because I asked him to) but nothing else ever since. He says hes not big into social media and everyone knowing his business which is understandable. But me being his girlfriend, I feel like I'm something in his life worth getting a post about now and then. Part of the reason I'm bringing this up is because today he got a text from his ex that I guess hes still friends with and that his sister is friends with. His sister announced her pregnancy on her Instagram and this ex sent him a text saying "your sister is pregnant!" Which whatever, she was excited for his sister but it got me thinking.. does she know he and I are together?? Does anyone really know he and I are together?? I kinda feel like I'm being hidden from people in his life. Like maybe he doesn't want people to know because I was once his sisters friend. But then again maybe I'm just overreacting about it all. I just need someone to ease my mind about this.

Update***

I see a lot of you calling social media stupid and saying I dont need a post because Its only important for he and I to know and whoever is in our lifes outside of social media. I dont push him or force him to post me or even ask him about it. It's not something I really care about all that much, I barely ever post on my social media apps just snapchat mainly. I guess it's more about the societal pressures to be publicly together that gets to me thinking about it more. It's not something I really think about ever but I just think the fact his ex texted him triggered the thought of like "does she know? Does anyone know? Shouldn't everyone know?" It just became a ripple effect in my mind. I don't want anyone to think these are thoughts that consume my mind everyday, they aren't. That's why I kinda needed the easing but I can see everyone's point on this.