I don't recall where abouts I found this but it caught my eye. The edge looks serrated and goes about 3/4 the way around it. There also appears to be pecking on the broad sides.
Thats a hard one looks very creek worn. You should see some of the worn out quartz pieces I find. Depends on the material if its a flint I would say it could be something if it is a Limestone or something along that line it is natural. Id hang onto it until you get some experience on the rocks in your area like if you find more in that shape but different sizes. When I 1st started looking I took my rocks and boxed them up. After a year or 2 of finding actual artifacts I went back through that box and was amazed that they were nothing but rocks, HA.
Definitely bears a superficial resemblance to the ancient Acheulian hand-axes, but it appears to be made out of dolomite or limestone; not desirable for making tools. Kinda looks like a chunk that spalled-out due to heat or freeze/thaw effects but not sure. Can't blame ya for picking it up.
Still looks natural, but to speak more broadly softer stone was often used to make digging tools (spades/hoes) and while your piece shows no signs of knapping, shaping, grinding, hafting or usage wear I wouldn't be surprised if there are thin flat sharpened sedimentary stone diggers to be found around Native agricultural settlements in your area. I haven't seen many but they can be surprisingly thin, sharp and well-formed, and honestly look quite effective for churning soil.