Probably because there isn't a huge difference between Home and Pro, apart from the price if you buy it. The main differences in Pro are to do with networking where network administrators have much more say in how Windows handles network tasks.
Windows 10 is still available as a free upgrade from Windows 7 and 8.1. If you download the ISO from the microsoft site:-
You get multiple choices on what you install. I only ever use Windows 10 home as I have very little networking requirements but I suppose if you upgrade Windows 10 home then the upgrade will be Windows 10 Pro.
I would check using control panel/system that your copy of Windows 10 has actually been registered because Windows 10 does work to an extent even though the licence hasn't been activated.