Is it wrong of me to suggest my boyfriend get a vasectomy?

I am 21 and my boyfriend is 25. We have been together for 3 1/2 years. We both have agreed that we do not want children. I know people like to say that we might change our minds and that we're still young, but I am certain I never want to be a mother, and he says he is certain he doesn't want to be a father. I have been on birth control for the entire time we have been dating. I think that it has affected my body, I gained weight but I am also tired ALL OF THE TIME. I don't like ingesting so many hormones every day, and don't want to have to keep doing it until menopause! I have brought up the discussion of him having a vasectomy but he gets mad and he says "Why are you talking about this all of a sudden?" and he doesn't give me a straight answer. Yes I know that women can get their tubes tied, but most doctors won't do that for a woman who has never had children. Plus, a vasectomy is less invasive and less expensive than a tubal ligation. I think it's a complete waste of money to spend 30 dollars a month on birth control. He just doesn't seem to care because he's not the one paying for it or having the side effects. Plus, I heard that birth control can cause blood clots. Should a girl never suggest a vasectomy?