Am I overthinking it?

Hi, first time posting on here so sorry if this is a little scatterbrained! Me and my SO have been together for about a year now and have moved in with each other. We both love each other a lot! Things have been going fine so far, but lately I've been getting jealous about little things, like him liking his old hook ups pictures, etc. And I really don't know why I'm getting jealous like that?? We're committed to each other so I honest to God have no idea why this is driving me insane, so much so that a week ago it got to be too much and I started to cry about it. Maybe I'm just hormonal? Any insight would be helpful