You must have heard about all the babies that got conceived during WWII when the husbands were on leave. Evidently enough interest and excitement can cause our bodies to break with the standard cycle. Even if you have regular cycles your ovaries are constantly recruiting new eggs into the maturity cycle so with proper motivation (husband back in town) there is a chance that things might be able to happen regardless of where you are in your cycle (except maybe during your period, it seems less likely).