Where is your place located (approximate city/state)? That is helpful to know when identifying plants.

North Florida

It is Hypoestes (Polka Dot Plant) and it is not native to North America, so it is an introduced plant to your garden. New varieties of Polka Dot Plant have very showy leaves and are grown as a housplant/bedding plant. My educated guess would be that your plants have been seeding around for years, and have become much more 'weedy' looking than the strains available now.

thank you!