My almost 3 year old, after months of not caring at all about the potty, suddenly asked for underwear on Saturday. We're on day 6 now of her in underwear, and except one accident last night (she seemed tired and distracted by Barney at dinner), she's been in underwear just fine. However, she keeps complaining that "her butt hurts" but points to her vagina. I don't see any signs of a UTI, redness or scratching (and ironically she's on antibiotics for an ear infection so a UTI is pretty unlikely in that regard anyway, I think). She isn't struggling to poop, though that is an issue for her generally and it might be that? (she usually only poops a few times a week and struggles through it). Any other ideas? She was crossing her legs last night, which is pretty unusual, but seems to be peeing fine. Could the antibiotics be causing a problem? She's almost at the end of the course, and just started complaining about this the day before yesterday.