Baby fall down on floor

I put my 10 month old son at baby dining chair and buckled then i put at our dining chair never secure.. i back face him cause i was about to blend his puree and i heard a loud THUD sound.. I turn saw him, he already fall down and his head at the floor while still being buckled to the baby dining table.. floor is those hard tile.. what should i do mummy? I feel so guilty.. no swollen or bleed but he cry for few minute then now he happily eating his dinner.. #advicepls