If my estradiol is 58 what does that mean?

Depends on cycle: The Estradiol levels vary dramatically depending on when they were drawn during your cycle. This value would be in the normal range early in your cycle during the "follicular" phase, but abnormal around ovulation. It is perhaps more important what the fsh value was on day#3. Even more important is the question "why were you having it drawn in the first place?".