I planted seeds directly from Roma tomatoes basically a few slices in the ground and covered with my soil. When they all popped up (probably 20+ plants) I thinned oyt and spaced about three hardy sprouts to grow...have others in small pots.

Two have started growing fruit...but are not Romas!
(The second photo they slightly resemble romas...but too big and not quite right.)
Why and how did this happen? I have grown romas before from a bought plant and in same way... Have had 'volunteers' come up from the bought roma plant... Always got romas.
I am confused and so are my plants!

Could your tomatoes have been a hybrid that looked like Roma? Seeds from hybrids are not true to type.

When tomatoes get pollen, they inherit the individual traits of the mother and the father. You can have a Roma pollinated by a Better Boy tomato and the offspring will have the traits of either the mother or father. Say you plant 100 seeds from the Roma you will get a split of offspring. You may end up with 25 Roma's and 75 Better Boys or the other way around. In order for the seed companies to make a strain and stabilize it,-- where every seed is the same,--takes many cycles or Season's of breeding. Hybrid or Heirloom seed are stable and you know what you are getting.