"Nails" in concrete floor, trying to lay vinyl plank floor...?

I have striped and removed all carpet and glue contents from my floor, now revealing the concrete slab. I have been laying vinyl plank floor. Well I have now gotten to the edge of the floor and noticed 2 small nail like studs sticking up. Well my plank there is not going to lay flat with these things sticking up...what do I do about this..and why are they there?