Recently our shower in the master bathroom has begun to squeak when we step in to take a shower. It is a fiberglass shower on the bottom and tile on two walls and glass for the door and above the tub. I have gone into the crawl space to check for leaks and I do not see anything. The house was build in 2005 and we live in Colorado so we have a fairly dry climate. How do I determine if I need to replace the shower pan or do I just need to call a professional and have it checked out? Thanks for your advice.