Hey, so i'm 16 and i had sex with my boyfriend at about 5:30am one morning, and we didn't use protection even though i told him to. I took the morning after pill at about 12:30-1:00ish that same day/afternoon. My last period was on the 1st and we had sex

Dear Anon,

Thanks for your question. Anytime you have unprotected sex you risk becoming pregnant. The most common side effect of an emergency contraceptive is changing the woman’s cycle. Side effects may include changes in your period, nausea, lower abdominal pain, fatigue, headache, dizziness and breast tenderness. Some women may have changes in their period, a heavier or lighter next period, or a period that is early or late.

This is strong medicine, that can change your hormones and may affect your menstrual cycle for a couple of months. It should only be used in an emergency and not as birth control.

Here are some resources I'd like to share with you.
https://www.empowher.com/birth-control/content/facts-about-emergency-contraceptive-pills?page=0,1
and
https://www.empowher.com/media/reference/birth-control-center

Best,
Helena