My 13 month old fell down the stairs

Ok let me start by saying it's all my fault I didn't put the gate back up this morning. My little guy has been walking since 91/2 months so I know how important it is. Well he was right next to me and I went to grab my hairbrush literally 10 feet away and I turn to hear the thump and cry. I immediately knew what happened. He didn't cry for long he is a strong guy. Has a few bumps and 2 bruises on head. I feel absolutely awful I stayed home from work so I could monitor him and have cried probably 4-5 times already about it. He played happily and is showing no signs of a concussion. Thank goodness. 😔