If you want to take a stat dose for your attempt (this is usually 30-60 mg meto), just take that dose and see how you react to it.
If you want to follow an "ahead" regimen for your attempt (this is usually 10-20 mg meto every 8 hours for 1.5-2 days), there is really no way to know if you will get EPS unless you complete the whole regimen, because in theory you might develop EPS at any point during this time, as your body becomes more familiar to the drug. If this is your option and you don't want to try a whole regimen test run (which I don't even recommend actually), just take as much as you would for a stat dose (30-60 mg), as above.
TL;DR: Take 30-60 mg meto and see what happens.