I don't have a period for 3 months and then had a small one and this months i have not had one and i been feeling things in my stomach?

Some thoughts...: In a woman with regular periods, some causes of a late period include: excessive weight loss or weight gain, increased exercising, emotional stress, having an illness, traveling, medicines (like birth control pills), hormonal imbalances, etc… For teens in their first 2 years of periods, pediatrician can help decide if anything needs to be evaluated. Pregnancy is a common cause of a missed period.