You have to accept the fact that you became an omega and are pregnant. That is the son of Liam (Alfa), your ex-boyfriend who broke up with you suddenly

A few years later you accompanied Ciro, your 5-year-old son, to play in the park.

"Dad! Look what Ciro found" Ciro said funny, he found a wallet

Not long after, someone approached you and Ciro "Did you see a wallet?" The person said they were panicking and it turned out to be Liam, your ex.