Well a few questions to first think of: are they around 2-3 years old? If so then it might be possible. They'll spawn once they're around 2-3 years old. Although, it isn't always very common, especially as it is almost impossible to tell genders.
Another thing you need to relileze about fish is that only Livebearers get "pregnant." There is a difference between pregnant and lay eggs. Goldfish are in fact, egg layers. So they don't get pregnant, they'll just lay eggs. If they appear a little round around their bellies, they might be getting ready to spawn. Be aware and watch out for little round eggs that look like these:
http://www.dkimages.com/discover/previews/739/119825.JPG
http://www.geocities.com/aquariumd/goldf1.jpg
From there on, do some research of keeping the fry. (term of baby fish; like puppy,kitten,chick,piglet, ect.) They will require some work on keeping them alive. But, just worry about now and worry about taking care of the fry if they even spawn and hatch. Okay? Good luck! x]
