my dd, 20 months, knocked her head very hard against the side of the loo and now has a huge lump on her forehead. Am panicking as I hate it when she hits her head and she has never had a big bump before. It happened 3 hours ago now. She hasn't been sick and is now asleep. She played very happily for 2 hours afterwards. What should I look out for? very worried as is night time now and so she is sleeping and I cant watch for any change in behaviour.