Unfortunately, it wasn't the nest in front of my place. I checked it again early this morning and nothing. It is overdue and probably not viable, sad to say.
Very likely not viable. I have an African Sulcata tortoise that I rescued about 10 years ago. She is reaching sexual maturity (she's huge and about 100 lbs. now). This Easter, I noticed she was backed up against the woodpile and digging with her back legs over a period of a couple days. I said to the wife that she was acting like a sea turtle digging a nest on the beach with her back legs to lay a clutch of eggs, which I thought was pretty odd.
A couple days later, I'm watering in the backyard and lo and behold, there's an egg laying there in the grass! Perfectly formed and everything. She layed several more during the week, but mostly I found them crushed. I knew they weren't viable because she's never been with a male tortoise. But, I did find it generally amazing that even though not viable, she was still going through all the natural motions of creating a new generation or torti!