Rib fracture recovery period (high school son)

My high school son took a chest X-ray at school last week...

I thought something serious had happened when I received a call from the health office the other day.

I heard there's something strange visible on the chest X-rayㅠㅠ

So yesterday, I hurriedly went to the hospital and got X-rays and a CT scan done...

Well, the 6th and 9th ribs are broken and are in the process of healing.

He said he fell while skateboardingㅠㅠ

I'm really relieved that there is no issue with my lungs, but it's been over a month since I fractured my rib.

When does this get attached?

The hospital said to see each other in three months, so will it be around that time?

It's been a month now... Are there any precautions I should be aware of?