If I have a son that is 18 and his mom pulls him out of a public school and starts home schooling him do I have to continue paying child support?

Depends on what your court order says.

It sounds like you are saying she is home schooling to continue to get support. But to qualify for home schooling the mom would need to meet certain requirements. So you go to court to end support.

My court orders say I pay until the first month following the date of the earliest occurrence of one of the specified: 1. child turns 18, provided that, if said child is fully enrolled in an accredited secondary school in a program leading toward a high school diploma or enrolled in courses for joint high school and junior college credit pursuant to section130.008, Education Code, the periodic child-support payments shall continue to be paid until the end of the month in wich said child graduates.

Well, did she get certified to home school?

Most home schools are NOT accredited, so I would say that your child support ended once the child was 18 and no longer in an accredited high school.

I would say by the terms of your agreement, a home school does not meet it,

BUT

It is likely because years ago when you wrote this, home schools were not popular and this was normally written in to make them go to standard colleges, not off the wall colleges.

So until you try and stop payment using this, and she may appeal that home schools are now normally reconised as a proper school ( allowed for colleges, military and more)
Also many home school programs are accredited so without knowing what type of program, you don't know it is not

I agree with the others. You cannot just stop payments. I would file a motion with the court to end payments at 18 or when the child was SCHEDULED to graduate with his high school class.