I can't get him to understand -_-

I'm almost 11 weeks pregnant and I've had a very huge decline in my sex drive. Half the time I don't even want to be touched. Which is so different from me normally, I usually have a higher sex drive than most men and I love love love affection. I literally can't handle it. I've tried explaining it to him and he just doesn't understand. Which then makes him mad because he thinks that I don't want to be affectionate with him. Example: he came home from work and wanted to kiss me but I just really didn't want to be kissed right then and I told him just not right now please. He comes back like a min later and he's like what about now so I give in and give him a kiss. I don't know if I'm overreacting but it's so frustrating. I just want him to understand that I don't want it as much right now and I want him to respect that and not make me feel bad for it. Am I being a bitch? What do I do?