You might do well to ask /r/askanthropology. Stone that can be flaked to produce a tool is often beaten up by nature and can appear to be worked. One of the clues as to whether people have altered the stone is whether the flaking is on both sides and especially if both sides have been flaked with a diminishing size of flakes to make for a sharper edge.

From what I can, this doesn't look like it, but I'd need to see more images comparing both sides. It is possiblye worked by human hands. I can't rule it out. But you need an expert flint knapper to evaluate your images.