how long does med school take?

4yrs for a bachelors degree

4yrs for med school

3yrs residency

8 years to become a medical intern (which is technically a doctor, but you have to complete residency before you are licensed to practice medicine on your own)

You don't become an OB/GYN [or any other specialist] in med school.

To become a doctor, you first do four years of college, then four years of med school, then at least four years of residency [which is where you specialize]. For OB/GYN it will be longer, because you'll first have to do a general surgery residency and then an OB/GYN residency or fellowship. It's one of the longer residency programs, partly because of the high-risk nature of OB.

To become either specialist, you'll have to work harder than you can imagine you could ever work, take out lots of loans [$150K is the "average" for new docs], and pretty much put your private life on hold.

med school alone takes 4 years at least after 4 years of undergraduate school

residencies can take 3-8 years after med school