What to do if i haven't had a period can it be?

Don't know your age.: Menarche usually occurs between ages 11 & 13 in the US. However for some their period could start as early as age 9 & for others not until 16. Before you have a period, you will have noticed breast development, pubic hair & white to yellowish vaginal discharge. Before the first period a girl may feel bloated, develop cramps in legs or abdomen & feel moody (depressed or anxious).

That depends: Indefinate. If you were previously having regular periods and haven't had one in several months please discuss with your gyncologist. If you have engaged in unprotected sex and your period is late- please take a home pregnancy test.

If you haven't had: your period for the last 3 months (unexplained) would recommend seeking gynecological eval. Can be sought earlier if desired. Take care.

Observe: I see you are age 53, so in the menopausal age range. You may not get a period any more, or it may become irregular, sporadic with variable flow. Keep your GYN provider informed.

Hmmm!: It would be helpful if you had elaborated. There are many reasons why a 19 year old would not have a period. It could be primary or secondary amenorrhea which are completely different things.... from absence of a uterus to pregnancy.