Hi, I Am Fourteen Years Old, And Got My First

Hi, I am fourteen years old, and got my first period last year. They used to be very regular, but the last four months, my periods have been irregular. The last time I got mine was two months ago, after actually waiting for two months for it to happen. Now, I have not had mine for a couple of months. I am starting to get slightly worried, even though I have never had sexual intercourse. Is this normal? What should I do?