Miscarriage and rainbow 🌈 baby...

I wanted to ask what your thoughts are on how ppl call rainbows 🌈 there babies after a miscarriage....

Long story short I always not really though anything of this until I recently lost our baby # 10 9/20 it was very hard since I was 8 wks pregnant now I know rainbow comes after a storm ( hard time loss) but then according to Bible it’s Gods promise to never flood the world again is rainbow and miscarriage something that the world made up can Christians use this as a gift from God rainbow or its wrong ?

It’s so confusing to me....