First of all, try not to stress about it that much, that could make it delay even more. Most of the time, irregular periods are part of the normal changes that can happen when you're a teen. At some point as you get older, your cycle will probably settle into a recognizable pattern. For the first two years I also sometimes didn't have a period for 2 months.
But keep an eye on it and if you notice anything uncommon like pain,consult a doctor. But try to relax and be patient :)