If you are already effacing and dilating on your own and the baby's head is engaged then squatting can make your water break. Keep towels hand and squat over them so you don't make a big mess. Best of luck.
You don't really want your water to break unless you are in active labor. Most providers put you on a 24-hr time limit to deliver your baby after your water breaks, which can lead to all kinds of interventions. Just be patient. Baby will come when he or she is ready. I know it is hard at the end when you are eager to meet your little one and stop being pregnant but just hang in there and it will be over soon.