It might fall anytime soon but it is difficult to give a specific timeline. Instead of waiting for it to fall, you can get it removed by your dentist. Once it is out, your options are removable and fixed prosthesis. Fixed can be bridge or implant. Removable ones are not so comfortable. Considering your age, you should go for fixed prosthesis. Implant would be the best choice for you.
Next Steps
Talk to your dentist about the replacement options and discuss in detail the advantages, disadvantages, cost involved etc.