Single Egg Clutch

Folks -- My hen, Pete, laid an egg 2-3 days ago, and has not laid a second. Usually, she lays two eggs like clockwork -- around 7pm on the first day, then around 4pm two days later. She sits on the eggs for a few weeks, then she and her mate, George, start courting again. Sometimes they get along and share egg sitting duties after she lays -- other times, Georgie remains in woo mode and gets kicked out of the cubbie (I give them supervised visits during the squabbles). I digress a bit ...

She and Georgie squabbled a bit after she laid the first egg -- some tussling in the cubbie. I have separated them. She has not laid a second -- she is sitting on the first.

She seems fine -- walking fine, no change in mood. Poops are normal, not the messy sitting-on-eggs-forever type, but usual tight droppings w/ good color. Also, her back is not hunched or bowed -- she looks like her normal slender self. I have read a bunch of threads on egg binding. I felt around Pete's cloaca (sp?) and looked, and did not see or feel another egg protruding. For a precaution, I have a heating pad under nest area, and rubbed a little olive oil around her opening.

Am I missing anything? Could this be as simple as she got a little stressed out and only laid a single egg clutch? Thanks in advance for any thoughts. You guys know my policy -- I always feel it's better to ask, even if I've read other threads on the topic.