My period hasn't shown up for 2 months and I'm worried

First of all I'm not pregnant.

The last time I had sex was in December and I have had periods since then.

The last time I had anything close to my normal period was March 26-29 ish. Some redish pink cum but that was it.

The prior months I got lighter periods but not like this.

Since March, I've only gotten a random short cramp here and there around my expected time but no blood.

I'm not on any prescriptions/birth control and I don't take vitamins/supplements.

I'm not sure what I should do, I'm getting worried but I'm away at school right now and I'm not sure when I'll be able to go to a doctor.