I don't have pictures of "building"; however, it isn't nearly as extreme as an ovulation. Building is more of a slow and steady growth. You won't see the drastic swelling that you see with ovulation. Also, look at the tails of the snakes above. The tails almost looks thinner then they did prior to the ovulation, hense the term "tail suck". Also, when they ovulate you will see the swelling underneath as well, almost looks like they ate the cat. In addition, my females will still eat when building and then stop a couple/few weeks before ovulation.

It's not really that big of a deal to mix up building with ovulation. If you do and mark the shed date you will then get an ovulation instead of eggs. Then you can mark the correct pre-egg laying shed.

Since I haven't seen your snakes and what they've been doing it's really hard to say if they will lay eggs or not.