It is difficult to tell if a goat is pregnant and generally requires a blood test or sonogram from a veterinarian. Look for a sagging over the tail head right before a goat gives birth using insight from a livestock consultant in this free video on goat care.
Tom Boyer, Chalk Creek Boers talking about how to determine if your goat is pregnant. The answer to that is not easy. It's much the same way as any human. You generally, in order to know for sure, you'll generally have to a veterinarian do a sonogram on your goat. Pregnancy testing in goats can be done with sonograms or blood tests. There's occasionally some other ways you can make those determinations. But generally those are the best ways to do it. You can not always tell by looking at a goat if she's pregnant or not. Sometimes they'll have a false udder, sometimes when they start to make up udders if you know they're bred, and you know that the belly is starting to develop then you have some indication that there's a pregnancy there, and that there will be a parturition. But it's not always difficult, I mean it's not always easy to determine whether that goat is pregnant or not. These goats here are pregnant, but you can't tell by looking at them. Once you get close to the one hundred and forty-five, one hundred and forty-seven days where the goat is going to parturite then it becomes easier to determine, obviously, at that point that the goat is pregnant. And to know when she's going to give birth, you generally can tell that by there will be a sagging right over the tail head, where those tail head muscles will sag down and everything will start to drop in preparation for kidding.