Need advice

Mattie
Okay so I am 16 and pregnant. (No judging please). And my boyfriend/baby dad's birthday is next month. He wants to have a party. Like with alcohol and anyone who wants to go. Admittedly, I get alittle territorial because there will be girls there. Girls who like him. And I have told him if this is REALLY what he wants to do for his birthday then he can. I've said it over and over hoping that he would get that I'm really hurt he would rather party for his birthday than do something with me. But I told him I wouldn't get mad about the party and I won't. I'm not mad. I'm just hurt. But his excuse is that it's his "golden birthday" (he's turning 19 on the 19th). And that it's his "last birthday before he becomes a dad" I understand this but do u really need a party with alcohol? Like seriously? You can hangout with your guys without alcohol. But I mean it really upsets me that he would rather get drunk than be with me on his birthday. All I wanted for my birthday was to be with the person I love (him). But I guess our priorities are WAY different. 
Am I a bad girlfriend for thinking all of this? Please help! I have tried to talk to him bug he is so set on having this big party that he doesn't even see how much it hurts me even when I say it does. Help please...