Thanks for writing to DoctorSpring.com with your health concern.
Actually common conditions such as stress, anxiety, unaccustomed exercise, fluctuations in your weight, smoking, drinking, late nights, erratic eating habits, travelling etc - can lead to irregular cycles.
Apart from that, polycystic ovaries, fibroids or hormonal imbalances ( particularly the thyroid hormone ) can lead to this.
You should be having a complete evaluation.
A rare diagnosis is early menopause, less likely at 30 unless you have had such a family history.
What you are going through is most likely to be a period of transient hormonal imbalance.
You should see a Gynecologist and have the following workup -
1. An internal exam - per vaginum and per speculum.
2. Pelvic transvaginal ultrasound scan.
3. Hormonal estimates - FSH, LH, TSH , Prolactin, blood sugars. Get adrenal hormones tested too if the ultrasound is suggestive of polycystic ovaries.
Please mention your height and weight.
All the best.
Please feel free to discuss further.