(CNN) As parents of toddlers know, nature doesn't always call at the most convenient time.

Brooke Johns was driving in Augusta, Georgia, when her 3-year-old son told her he was in urgent need of a bathroom. She pulled into a gas station parking lot, only to realize that they wouldn't make it to the restroom.

"He says, 'Momma, I'm about to pee in my pants!'" Johns told CNN affiliate WRDW.

Johns was 34 weeks pregnant and couldn't carry her son, Cohen, to the toilet. So she tried to cover her son up as best she could while he peed in the parking lot.

"He was peeing before his pants were even all the way down, so obviously he had to go," says the mom, who lives in Beech Island, South Carolina.

Read More