If any of your tomatoes fell to the ground and overwintered their seeds, it's certainly possible that you have volunteer tomato plants from last year's plants.
One year I threw my Roma seeds/jelly goo into my not-hot-enough compost. When I then used the compost the next spring, all my roses had HUNDREDS of volunteer tomato plants.
The pulled-out tomato bodies went into the compost, but since then I've been a little gun-shy about putting tomato seeds into the BioStack. Maybe this year, since it's a hotter heap than it used to be...
USDA Zone 9, Sunset Zone 17