This depends on what kind of pills you are on. If you are on a pill that has the same dose all month long, then you will be able to skip your period. If the dosage changes every week (like with ortho-lo) then you won't be able to skip, it's just the nature of the way the pills afect your body. Also, you can skip several month safely; just think about the depo shot, or seasonale.
There is no data stating whether or not skipping many periods is bad for you. However, as it is a natural cycle of the woman's body, at least 4 a year is probably the lowest you shoudl go.One of the depo shots lasts 6 months, but 2 periods a year just seems too few.
Since you are on a pill that is the same amount of horomone each day, you should be able to skip. This may cause spotting all month long however, which would of course defeat the whole purpose.