This argument is the continuum fallacy. I would suggest you read about both it and the sorites paradox.
You can't apply an arbitrary cut off date to a fetus, because nothing can not be a person at one second, and magically become one the next.
And I never said they could be. It is a continuum. Please read what I said again:
So no, a fetus obviously isn't unconscious at 23 weeks, 6 days, 23 hours, and 59 minutes, and conscious at 24 weeks. It is a gradual process over the space of 2 weeks. If you make the cut off 24 weeks, i.e. before that process has begun, then you can be sure the fetus is not conscious since it does not have a cortex.