What do you mean by weird?

I didnt start getting my period until I was 15 and mine was really weird. Sometimes I would go for 3-5 months without a period, then they would only last about 4 or 5 days and they'd be really lite. They didnt start getting normal until I was about 17 then they were every month around the same exact time and they were heavy. It's normal when you first start getting your period for them to be weird and sparatic so I wouldnt worry. But if its really bad I would just suggest consulting a doctor.