Personal but curious

So I don’t know my boyfriend has never really been sexual with me like I am with him , my sex drive is normally high but since I found out I was pregnant it just seems he really doesn’t even seem interested in sex at all…usually I make a big deal and feel insecure but I’m blessed with my baby and I’m not trying to argue…I was in the shower tonight and I decided to play with myself a little and it cause some cramping in my pelvis , I remember this happening my second pregnancy I would get worried but nothing would happen I’d just get sore ??? Lol idk is it cause everything is changing down there?