I agree on maths being a human construct formed from the observations of the behaviour of the universe. There's nothing really "objective" since we can't compare this behaviour with respect to an absolute reference outside of the universe. But hey, it's managed to predict outcomes pretty accurately.
I also prefer "creating" rather than "discovering" new concepts in maths. Going from the above points, maths is really more a tool for determining the properties of the universe rather than a natural phenomenon of it. It's a "creation" rather than a "discovery" to me.