there are some very informative videos on you tube about palpating. they may help you. i know when i first started i wasnt squeezing hard enough in fear of hurting the snake. if you watch others you get an idea of how hard you need to be. you wont hurt them. and yes they seem to dissappear after a certain size and you wont be able to feel them after she ovulates either. but you will begin to see egg lumps before she lays which is cool.
adam jeffery