mouse position property set mouse position according to whole screen instead current windows form

Question

Hello I have a windows form. I want to show a popup at the position of mouse but when I get the mouse position with mouseposition property,it doesnt show right below the cursor. When I click the cell the popup should appear right below the cursor instead it shows at random places

I have a code like this:

Point p = new Point();
        p = MousePosition;
        if (e.Column.Name=="colnot_detay") 
        {
           labelControl1.Text=gridView1.GetRowCellValue(gridView1.FocusedRowHandle,"not_detay").ToString();
           popupContainerControl2.Location = p;
           popupContainerControl2.Show();
           
        }