What should I do??

So me and my boyfriend have had issues with him liking his ex's Instagram pictures when he promised he wouldn't .. But recently I found out he's been looking at her tumblr legit everyday since then. I noticed he looked yesterday afternoon. I'm not sure if they're talking.. I highly doubt it. But should o say something or even be worried? Am I being alittle extra and up tight? It just makes me feel like maybe he doesn't love me as much and still loves her.. He told me he doesn't, he just misses things they use to do and not her in general.. Idk..