You are worried because of a long break.
That is completely understandable!
However, it does not have to mean you are sick.
Many girls have irregular periods at the start.
Sometimes the break between periods is short.
Then it may take a very long time until the next period.
It can often take some time until your period comes about once a month.
Usually the break is between 21 and 35 days.
For some girls the breaks are either always shorter or longer.
However, there could be another reason.
For example: if you are stressed.
If you have taken medicine.
Because your weight has changed dramatically.
If you have already had sex:
Then you may also be pregnant.
If you are uncertain you can see your gynaecologist.
They can examine you and answer your questions.