I also secured a position four months before graduation on a verbal offer. The nurse manager was so excited to offer me the position that she took me down to HR directly after my interview, which was a couple of weeks before I actually accepted the position. I, too, had no written offer but felt very secure with ths situation. I received all my written information when I did my preemployment physical/paperwork. If the lack of a written offer scares you, definitely voice your concerns to the recruiter or nurse manager as llg has said. That is excellent advice. I believe a phone call or personal visit would do better than an email so that you can effectively convey your feelings, ask and answer questions, and get immediate feedback. Good luck.