My parents aren't letting my boyfriend and I talk or see each other while I'm pregnant

I'm a senior high school student. I'm also five months pregnant. I got pregnant by my boyfriend of three years. My parents don't want us to communicate with each other. He can't even come to visit my gynecologist. My mom goes to attend all of my doctor's appointments. She's supportive of me. I wish, though, that my boyfriend was next to me and be able to see his daughter on a sonogram, at the very least. My family does not understand that he deserves that much. I cry all the time because I feel lost and hopeless. I need guidance and I believe that you can give it to me. Am I wrong for wanting him around? Are they right for keeping him away from the appointments and not letting us communicate with each other even though we are the parents? I do everything that they ask of me. I just want him to be around. When I ask my parents to let him be here, they call me a selfish person. Please help me.