Gas pedal floored, then there's cough-like sound and gasoline smell inside car

[Silversurfer_yaris]

I have a 2016 Toyota Yaris with a 1.3L engine (2NZ-FE). Bought this used in August 2020 and 2 days ago, in the expressway, I floored the gas pedal / accelerator and it produced a cough-like sound and it smelled gasoline inside the car. So I released the pedal, the smell went away, the cough sound went away, no check engine light, and drove smoothly for another 30kms to the house. There were no vibration nor engine power loss. This hasn't happened before to me even with my other cars. Anyway, I drove it again this morning for about 20kms, and it's still drives smooth.. One thing is for sure, I won't floor the gas pedal anymore!

Should I be worried? What could it be?

Thanks for those who will respond.