No, he's not pregnant again. This happens to omega's when they already bonded with an alpha.
ohhh... is that why Dojin wasn't afraid of him running away again? Cause he knows they're bonded so he's not gonna be able to cheat on him?
I don't think Dojin knows that Hyesung is bonded with him. I think Dojin considered the sex and saying he loved him as a question to Hyesung - asking him if he would stay with him and when he discovered Hyesung was gone he took that as his answer, that answer being no. I think that was good character development from Dojin, he loves Hyesung, but he is willing to fully respect his decisions and let him go.
When your an omega and you bond with a alpha, you can't have sex with another breed because your throw up. Your body is already connected with that alpha. That is your bond and you can't break it. Your body will do that on it's own. You can't stop it.
wait, is he pregnant again?! Σ(っ°Д °;)っ