Is it okay to opt out of getting a flu shot?

First of all, I'm not the person thinking it's dangerous to get one, that it will mess me up in the future like all of those crazy young mothers. But anyways, I just don't want one, I've never had one either. Though I do believe younger children and the elderly deserve to get the shot.

I think mainly the reason I don't want one is because there are many other people out there who need it more than I do, and there isn't an unlimited supply of this stuff.

I just think someone else who needs it more should get it. And also I have this little fear that I could be allergic to the shot, since I'm allergic to pain killers, and i don't know what exactly in it i'm allergic too since my doctor, even my allergist said just to avoid it since i never had a deadly reaction and there will be no point in testing it because it may be inaccurate.

I'm 20 years old, Male, and pretty healthy overall.