It's extremely hard to tell if Jessica Biel had a nose job. In this before and after picture, it doesn't really look like she had plastic surgery. Also, if you rewind even further back, her nose looks the same then. The reason people think she had a nose job is because it simply doesn't look natural. Her nose looks a little jagged and is too thin. It just has the look of a nose that was operated on.
Here's Jessica Biel has a young actor with the same looking nose. If she had plastic surgery, it would of been when she was around 18 years old.
Again, we can see her nose in two different lights, but it still looks the same.