new to nursing and rehab

Hey to all. I just graduated in may and started working at a university hospital. We have a good size rehabilitation department but i'm not sure it's the perfect fit for me. I'm doing an internship which lasts 4 months and will then need to make up my mind about the job. I really enjoyed my med-surg rotations and took the internship originally for a gi/renal/pulmonary unit but had to switch because they didn't have any preceptors for me. How long should i give it to really know if it's a good fit for me. I've been doing it for 2 weeks. Thanks for your help.