For those who have never seen an ovulation here are a few shots.
Note how the belly pattern is being pulled up the sides of the animal as it is being stretched. Also of you look closely you can see the individual scales being stretched apart.





Again you are looking for stretching and an area around 2/3's down the body that looks way larger than the rest of the snake like an internal explosion. IMO if you have to ask you haven't seen it, it should be that obvious. Even in my pics some don't look that obvious but in person there was no denying it. All the girls in these pics dropped successful clutches.