Need ID help

This is a small plant we have growing in our garden recently and I pulled it like weeds, but noticed the minty smell, which reminds of tea tree oil. We have different kinds of mints like spearmint, chocolate mint, even cat mint and lemon balm growing in our garden. But this one is much smaller, like a very wild plant, that has less blossoms and practically grows in any crack of soil. Leaves are thin and also not as serrated as real mint.