Im nineteen, and Ive had regular, on time, periods since I was twelve. Just recently, last month, my period came four days late, and Ive never been late before. This month its currently six days late without any signs of showing. Im virgin, and Ive had no type of sexual intercourse before in my life, so it can't be an STD or pregnancy. Tell me what's wrong, please?

If you are a virgin, it most likely be a hormone shift causing your periods to change.