My girlfriend has been off the pill for 4months cause she missed getting a new pack from her doc. she is worried about no period for 4 months. pls hlp?

Might need preg test: Pregnancy is the most common cause of a missed period. If not pregnant, other causes of a late or missed period include: excessive weight loss or weight gain, increased exercising, emotional stress, having an illness, traveling, medicines (especially birth control pills), hormonal disorders, etc… A visit to one’s Ob-Gyn doctor is a good idea if symptoms are persistent, recurring, or worrisome.