Sometimes it would bother me, sometimes not. What matters is that it bothers you and you have every right to be upset. He can't justify wanting it but not you when you're ready and willing and he knows it bothers you. (well, he might try but no good reason) I don't know what to tell ya but don't feel like you are the one in the wrong, cuz you have every right to your feelings.
my husband and i have sex 3-4 times a week when he isnt working his butt off (has a hell of a commute). it was almost every day until my last trimester. the only time i got mad at him for watching it was when i wanted it but he didnt and then i saw im watching it. BUT we talked about it and what he didnt want to tell me is that his back and legs were hurting (which happens alot). he knew he couldnt "preform" like he should. and honestly sometimes with the baby its just way faster for him to do it himself with porn. talk to him about it. as long as he isnt hiding it. my hub was hiding it at first bc his ex would FLIP OUT if she caught him watching porn.
on the other hand my ex could not preform at all without watching porn. but i think that is because of his sexuality.