S3 Presigned URL: How to know about high traffic situation?

I have a scenario where my images are getting uploaded on S3 bucket using pre-signed URLs. In case of high load scenario, I want to let my user name about delay and ask him to wait. After expiry period we get HTTP status code 403, but I just want to let him know about the high traffic situation

but question is

1. How do I find out the time taken by image to be uploaded on S3 pre-signed URL?
2. What all status codes can we get from PUT request on S3 pre-signed URL? (if can help me with some documentation for same; https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/S3.html#getSignedUrlPromise-property does not have info about different status code retrieved from AWS)
3. How can I know about high traffic situation on S3 bucket?

How do I find out the time taken by image to be uploaded on S3 pre-signed URL?

This shouldn't matter. When the S3 pre-signed url expires, it will not stop uploads in progres. The expiry date is only important to initiate the upload.

How can I know about high traffic situation on S3 bucket?

You can't check this as this is AWS internal networking backend. you have no access to it nor AWS publishes such an info. The only issue is the speed of the internet connection of your clients.

What all status codes can we get from PUT request on S3 pre-signed URL?

I'm not sure what do you mean here.