More than likely she is just gravid and what you saw was her ovulation. All the signs and timing line up for her to be gravid. Feeling eggs is a lot harder than feeling developing follicles so I wouldn't rely on that at this stage. They would be about golf ball size and softer than a few weeks ago.
How long ago was this swell, and has it gone down? This is the main thing I would base it on. Ovulation looks like they swallowed a small toy football or really large meal, but in that 2/3's down area. After ~24 hrs will drastically decrease over the next 24 hrs. That area will still appear to be swollen for the remainder of the time till she lays, but you would expect it to go down to how it was just before ovulation size and slowly build up again, and as it swells again it's going to be more spread out rather than one big lump.
I would avoid any kind of soaking unless you have good reason to suspect it's constipation over being gravid. Hopefully it didn't cause problems already and the water was in the right temp range. If you end up with a lot of slugs, this would be the likely culprit. I certainly don't mean to cause you more worry, what's done is done, and I certainly hope you get all nice healthy fertile eggs.
I would also cease handling her at this point unless absolutely necessary, and generally bug her as little as possible to keep her stress level low. When you do handle her, give her a lot more support underneath than usual and be gentle.