I am now officially a mother. I have called Poison Control over something Drew put into his mouth. Rest assured: he's fine. He had managed to get his grubby little hands on a tube of diaper rash cream, which he then opened and squeezed some of the cream out. When next I saw him, he had cream on his hands and face and all around his mouth, but very little seemed to have actually gotten inside his mouth.
I got him cleaned up and consulted the back of the tube for what to do if the stuff was ingested. It said to call Poison Control. So I did, and they said that the worst that could happen was he would vomit, and then only if he had eaten a lot. For the next hour, they told me to make sure he never laid down on his back (so he wouldn't choke on any vomit) and to give him some water.
Check and check. No vomitting, no strange behavior. Our first and hopefully only brush with Poison Control turned out to be completely preventative.
I feel like I've passed some sort of milestone.