pregnancy advice

so for about two months now me and a mutual have had a typical fwb relationship, we’ve always used condoms but like i’ve always heard they’re not 100%. i’m about a week and a half late on my period and i took 3 pregnancy test and they’re all positive. the problem is i’m a junior and he’s a senior, i just turned 17 and he’s almost 18. i’m so conflicted on what to do and how to tell him, i’m sure he doesn’t want a kid right now and i’m so scared he won’t stay in the babies life. any advice on how to tell him?