First things first. Calm her down, provide emotional support in a professional manner. You should only inform those people in the chain of command who need to know. Her information should be kept confidential. Usually the individuals who would need to know are: Platoon SGT/LDR, Co CDR/1SG. You may be able to involve fewer people depending on the specifics of the situation. If in doubt see your 1SG and discuss the matter with him. Next, let her know that one way or another she will get through this and be stronger for it. The first issue is to find out if she is actually pregnant. There is no sense in wasting emotion and energy on something that may not be an issue. Have her buy an over the counter pregnancy test. Once you have the results from that, have her go to the medical facility and take an actual pregnancy test. If she is not pregnant she has learned a hard lesson in life. You need to follow up with her and discuss the issue and how to prevent this problem in the future.