How can I tell if my goat is pregnant?

You will notice their sides poking out (similar to human bellies when preg) and their utters will begin to start sagging. When did this happen? Usually the mating time is around August to December. Also, one way to know if they are in heat is if the male starts sniffing back there and his lip curls -- wierd i know but it really happens that way. They usually stay pregnant around 5 to 6 months and then one day BOOM you have a baby goat or 2 or 3. They have multiples often. Let me know if you have any. We may have a goat that is pregnant now.