i wonder why MC just let Chase to cum inside him, knowing he's gonna go preggy again

I dont think hes gonna get pregnant just from having cum or semen inside him since in omegaverse, an omega (as far as i know) only gets pregnant when an alpha knots them during sex or during a rut.

In this universe, extreme alpha can control their fertility.

Guess you missed that part where he knots him lol Josh even mentions it. Probably still won't get pregnant tho since Chase isn't in rut like last time