Pregnant

So I just recently found out I'm pregnant with baby #3 SO has no idea we have 2 kids already together a little girl born in 2018 and our son who was born the end of May of 2020 now im expecting baby #3 dad I dont know how to tell him considering he's been 100% honest with me recently he didn't want anymore babies I was on birth control taking brileene only reason why I knew something was off because I started leaking colostrum and I honestly haven't had a period since may I wanna say I had spotting every month so never thought anything about it and now I'm lost and I just don't know what to do at this point my SO is 27 will be 28 in a month ill be 22 in Dec i could of had my tunes tied after my son but we didn't want to in case years later we wanted another baby and he has no insurance so he's not able to afford a vasectomy and now I just don't know what to do my son is only 15 months