I’m pregnant

I got a test done that came back as positive & my mind has been flooded with different thoughts. Mainly, to do with my partner. We’re only 22/21 & we’ve spoken about the chances of me falling pregnant. He’s always reassured me but I’m still scared now that it has happened. A lot of girls my age would think they’re not ready, before I found out I was pregnant I thought maybe I could go ahead with it but it’s dawned on me, it’s real & it’s scary. Should I tell him ... how should I do it ... I just need opinions