Hi there. No, no need to worry. This can happen to the most regular of people from time to time. Hormones can do a blip and we'll have an unusually long cycle. Things can be involved like changes in routine, illness, stress, losing or gaining weight, etc. or it can just happen out of nowhere. If you go three months without a period, then maybe schedule an exam with your ob/gyn but still it is really not anything that would be a major issue but perhaps a hormonal imbalance or a slow thyroid. If you have symptoms of it coming, it probably will any day now. good luck