What could be reason in this?

31 years old female came with complain of amenorrhea since 2 months
Hb:7.5
General body weakness with giddiness, vomiting
UPT :negative
What could be reason in this ??

Pregnancy is the most common cause of secondary amenorrhea, although problems with hormones also can cause secondary amenorrhea. Treatment of amenorrhea depends on the underlying cause

About nine to 14 percent of women in the United States are affected by menstrual irregularities. With the exception of missing your period while on some contraceptives, it is not normal to go without a period for several months and can be harmful to your health. Visit your physician if your missed periods persist