Baby swallowing pool water ?

FTM and probably just worrying too much but- my son was in a wading pool today and he fell back twice and took in some water. He didn’t really cough and then was running around on the playground after totally himself.

When we got home he wasn’t really hungry- which is mostly normal for him when he’s tired. He drank his usual milk but he’s woken up a few times crying in bed. He normally sleeps through the night.

I’m wondering should I feel worried or just try to relax he’s probably fine? I stupidly read about dry drowning ....

I feel like I’m not going to sleep at all tonight now I’m so stressed. Help!