Tutu, so far only went for one lesson. I think for first time mummy and if u are the type that don't read up (same as me), then going for prenatal classes would be useful.
If u r taking Wong boi boi classes, better book earlier. Actually, with all the hype abt her, felt that it was overrated. And the class size is huge - squeezed like ants. When I sit down on floor, my toes were touching next couple's mat. Maybe it's cos mine is a weekend class.