You're determined to worry, aren't you?When they need to go, they generally do.
And keep in mind that if your snake is young, it's eating younger prey which is MORE digestible (meaning less waste to expel after digestion), so it can just take longer
before your snake feels the need. OK?
Remember that snakes have evolved to survive harsh environments, which means their bodies conserve both food & water to survive.
(so you won't see snakes having a pee'ing contest with each other)