Pre pregnancy exam

I am considering making a pre pregnancy exam in a few months. I have been doing a little research on what goes on at pre pregnancy exam and I have found that it is suggested to get certain vaccines before you get pregnant, such as Rubella and flu shot. I am more of an all natural person when it comes to medical practices so I really don't think I will want to be vaccinated. I don't do flu shots since many people still get the flu, even with vaccines. I just think what is the point and I like building up my immune against them, letting my body take care of it. Any ways, is it crucial to have these vaccinations before conceiving or is it ok to not get them? I rarely get sick and have never even heard of Rubella.