Dr Bronwyn Moore (gynaecologist) answers:
Cycle irregularities are quite common in women not on the pill, and many things can delay a cycle. Stress is a common cause for a late or skipped cycle. Changes in weight, diet and exercise are also common causes. International air travel may also disrupt a woman’s cycle. If you, at any point in the cycle, used an emergency contraceptive (morning after pill) this can also delay a period. Occasionally during a cycle ovulation is disturbed, causing the development of a follicular cyst – this is a simple cyst usually smaller than five centimetres, which produces enough hormones to delay the period. These usually resolve on their own and no specific treatment is needed. Of course it is possible that you were pregnant and had an early pregnancy loss, and if you had a positive pregnancy test in this time that would confirm it. Also if you had any pregnancy type symptoms this would be more likely. If this were the case the period which follows is usually a lot heavier than normal. If you had any pregnancy symptoms, go see your gynaecologist to make sure that there are no problems.