Missing a period for 2 months straight, why?

[Levi_Kettle]

Hello, I've been missing My period for two months straight, I'm a normal weight and have been around the same weight for a year.
I am only 13 but have had my period since I was 11 and a half(sucks huh?). It's started to worry me since my twin sister had gotten hers both times, she and I are the same weight and have almost identical looks and heights, only thing that is different is I have TMD (Temporomandibular joint dysfunction). It only effects from my head to mid-back and I don't believe it would effect anything.
I am not stressed in any way, I'm good in school and am easy going around parents, teachers and friends.
I am a virgin, I don't even have a boyfriend. I've had no sexual contact with myself or others, so with that said, I am completely clueless as to why I am missing it, and am only now starting to worry.
Am I pregnet, or is it something else?

[kellopp]

If you haven’t had unprotected sex, there is NO chance you could be pregnant. It’s probably stress. Make an appt with a gynocologist.

[Levi_Kettle]

Okay, thank you so much!