The easiest thing to do to tell if it is your water or urine is to put on clean, dry underwear and a pad or panty liner. Then you'll want to lay down for about a half of an hour. If the fluid is amniotic fluid, it will pool or gather in the vagina while you lay down.
During this half an hour, spend time gathering your thoughts. Are you packed and ready for the trip to the hospital? Do you need to call anyone like your partner or doula? Try to do a fetal kick count or make note of your baby's movements as well. You can also use the time to take a quick nap.
At the end of the time, simply get up and go back to the bathroom. Here is where we checked to see if the pad is wet or dry. A dry pad means that your water is most likely not broken. What you experienced could have been an increase in mucus discharge, a small leak from your bladder or other common late pregnancy nuisances.