What does pinkish and brownish discharge when wiping mean after a late period?

Anovulation: It is common for young women to miss periods, due to anovulation (not releasing an egg in middle of menstrual cycle), especially with excessive stress, weight loss, or exercise. Without a period, the lining of your uterus continues to thicken, and can shed spontaneously, and after sex. However, persistebleeding after sex can also be sign of sti; missed periods can be pregnancy or other condition.