I think I have noticed the same thing. It's not on geckos but ball pythons. At the beginning of March I have noticed a lock. The female have shed 7 days ago and is busy going through a drastic color change. I can't think that she will be laying eggs soon but all the signs are there...
Temp is pretty stable in the room, rack is coveredt o maintain heat and last matings were round Feb/ Mar. I wonder if the eggs are fertile. I will candle them at two weeks.
I had some maiden unbred fat tails that did not undergo a chilling period last year that started to lay in July on their own accord. I did not chill or breed them because they where undersized but mother nature and them had another plan. Some laid consitently through the season without a single mating, while other in the same rack and conditions did not lay.