Does egg fertilization usually happen before, or during the "building" process?

I have a female that looks as if she has been building for a few weeks now. She locked up with my male two or three times I believe before she took on a very plump, rounded out look. She also began glowing (looks like a different snake). When I hold her vertically, I can clearly see a "pot bellied" look throughout the bottom half of her body to her vent. In my "first year breeding naivety," I stopped cycling her with a male once I noticed her glowing and very rounded out look, thinking she had already ovulated.

My question is now, did I screw up my chance of fertilizing these eggs? I put her back with the male a couple days ago when I realized my mistake, and they locked up right away. She is the only female so far that has taken on the glowing and "fat" look, although all my females have been locking. I'm afraid that since I have not been cycling her with a male for the past few weeks while she has been building (I assume), I blew my window at getting the eggs fertilized?