Depends on how far you've played. If its Ep3, you can get Ep4 by waiting a bit or by becoming a 10$+ patron. As for Ep5 it's still in development and has suffered some delays.
Have finished the game and I would say it's awesome. The storyline is great I like how you're given the option to corrupt or show affection to the characters. The japanese doctor is also perfect, and I hope we get some explicit scenes with her as well, maybe when the main character gets back to the hospital to get his cast and stitches removed? I felt that she's on the verge of being corrupted on the scene with Emily. Please keep up the great work AZ!