What Causes A Left-sided Bump On The Head After An Injury?

Hello, I would like to ask about my daughter s condition. My five month old daughter fell off from the bed yesterday noon. She cried immediately after she fell so I carried her to calm her down and she did. But I can t calm myself down for what happened, I waited for my partner to get home so we can take her to the hospital. While waiting, I continued observing my daughter if she would still act normally which she did. She drinks her milk and still moves around like she used to but I m still worried. It s the first time that something like that had happened. We took her to the hospital and the doctor said she s okay. They didn t recommend a CT Scan because my daughter shows no sign that she needed to be scanned. But I m still worried. There s a bump on the left side of her head, right above her ear. It s soft to touch. Should I be alarmed about it? Or is it normal because she had a fall and will eventually subside/heal on its own?