Tonks had anticipated the possibility of something like this happening, which was precisely why she hadn't wanted to tell him until after the meeting was through.
"There were more important things to focus on," she said. "I Apparated here, so I assume I can Apparate back. It didn't hurt the first time." She hesitated. "I don't know. Hestia already knows--don't be mad, but I told her before just in case. She can if she wants, but my mum can too, if Hestia's got better things to do." Like help the Order get the Muggleborns out of Hogwarts. "I'm okay, I promise. Really. They're a while apart still, and it doesn't hurt much." It was a few weeks early, but that wasn't all that unusual from what Tonks had heard, and for all she knew, it really was false labour. The embarrassment of a false alarm was what made her hesitant toward calling in reinforcements, so to say.
"Don't panic, okay?" she half-begged. "If you panic, I'll panic, and I'm trying really hard to keep my cool right now."