Am I just being hormonal?

So the other day for some reason I was playing on my SO's phone...I think mine had died. But while playing on it I was being goofy on snap chat and of course looked at who he was chatting with and stuff. Well it was mainly girls...I know them and don't have a problem with most of them but there is one that I have specifically asked him not to talk to her. She is very messy and has a not so great past(she likes people in relationships)

So I asked him what was up with it and he got a little defensive but told me to just delete anyone I didn't want on there.... -_-

Well when we got home my mind was still on it even though it had been addressed so I went on his Instagram. Right away I saw he was following pages of naked women. All skinnier than me of course (I'm 20 weeks pregnant) and it just makes me cry. I shouldn't have been looking but I did and now I wish I had not. I don't know why it upset me so much but it did...

I went to take a shower so he wouldn't notice because it was my fault for looking and I didn't want him to feel bad but he came in the bathroom and asked what was wrong. He ended up in the shower with me(his clothes still on) trying to comfort me. We talked for about and hour and I explained how it made me feel....so he goes and deletes his Instagram.

I feel bad because I don't want to be that girl that doesn't let her guy have a social media life...but he insisted on deleting them.

Well this morning I guess I wanted to prove that maybe he was just being a guy and I was reading into it to much so I went to his Instagram through mine to look at some of his post and stuff.

Of course none contain any sign of me or baby but what hit me the most is one of them was "liked" by one of his ex's. This ex in particular has talked down on me since day one. She is skinny and beautiful and I've always been worried because I can't compare to her... we are just too different. But I go on her page and see that PUBLICLY they have been liking each other's stuff. I know I know it's just likes blah blah blah but reverse this whole situation and it would be completely different. If I even followed or were friends with an ex he would flip his shit.....

I just feel so dumb for being upset but I feel really really hurt...

Do you think I'm being dumb and should let it go?