To follow the plan, yes, you only get three servings of veggies.
That being said

If you are tracking everything you eat (every BLT, bite lick taste) as long as you get the right Nutrients, it can be done. Search the medifast boards for a post titled "Detailed listing of nutrients needed - need it ASAP" in the "Registered Dietitians Support" forum for the complete list of nutrients (I can't link yet). BUT this requires faithful tracking of everything. Thus why they created the three veggie rule (so we don't have to label analyze everything).