Pregnant

Long story short my doctor told me I only had a. 5% chance of ever getting pregnant and I am on the shot for birth control ... so we assumed I would have to have ivf when we were ready cause I'm 17 and he's 19 but now I'm pregnant and neither of us are actually ready but this is such a miracle but I have no idea how to tell him .... I'm freaking out cause he's gonna be pissed does anyone have any idea how us could tell him?