i need so help and advice

my period waa supposed to start today and it didn't, i been having sore breast and nausea so i decided maybe i should take a pregnancy test so i took one and me and the guy are not together and hes my ex, we had a pregnancy before we broke up and we lost it, and it's been a year since then, we don't talk alot and it was just a night, I'm terrified from what this app says I'm 3 weeks 6 days, what should I do, how should I tell him I'm scared.