Draco furrowed his brows, but didn't argue with her. Hermione was much better at sensing magic than he was. Growing up completely surrounded by it had left him with a general sense that it was always there. It was when there wasn't local magic around that he felt nervous and unsettled. If she said she felt a change, then she did.
He brushed her hair back and gently settled his hand on the back of her neck, as she'd asked. Deliberately, he used his left, so that the band of his wedding ring would touch her skin as well.