airport pat downs

when given the choice i would choose a body scan over a pat down at the airport any day. when i flew out of new york last week i went through the body scanner. when i left the midwest on monday i was given a pat down and i got the feeling that it was only because i was wearing  a skirt.  when the airport security woman  saw me she decided to do a pat down which was only on my  legs. i briefly googled how to avoid an airport pat down and one of the things listed was for women to wear pants , not a skirt at the airport. i do not wear pants, but i do not want to get singled out for a pat down at the airport every time i go through security only because i am wearing a skirt.i think that this is discrimination.