I'm 18 years old, and my period came a week early and only lasted two days. I'm not sure if it's over yet, but the signs that it may be are present. I've been reading some articles that have hundreds of reasons that could be the cause of this early and short period. I've never had sexual intercourse so I know that it can't be implantation bleeding or anything related to pregnancy, right? Can anyone help me put my mind at ease by telling me what this could be and if they've experienced this before?