If it was a fossil, it should have some surface features indicative as such (we cannot make that statement absolute because some soft-bodied organisms with featureless exteriors do, rarely, get preserved as fossils).
The only surface feature I see is a faint circle, which is suggestive of a sedimentaty layer intersecting the globular object. If that interpretation is correct, the object is most probably a concretion. That might have a fossil as its nucleus, but it is mainly mineral rather than fossil.
I know it looks 'organically' round. We often see concretions of such a shape. Some are egg-shaped, which also causes folks to think they are fossils. In most cases, it is just Nature playing games with your mind.
The little one to the side... That's probably of the same origin.
Please see my explanation of concretions at the end of this topic