Period was 6 days late this month. its lighter than usual and shorter than usual lasting 3-4 days instead of 7. never had sex. whats wrong? scared

Brief period ?: If "never having sex" means not having intercourse or exposure to semen at all, then pregnancy is not an issue, but if you have been with a male who may have ejaculated near but not inside the vagina, pregnancy is possible. Wait another week, and get a serum HCG test if pregnancy is possible. If negative, your cycle will probably resume normally next month.