###Human: What is the reason for delayed periods? ###Assistant: Hello. If your prime concern is pregnancy alone, then you can get a serum beta hCG test done which is the gold standard and conclusive. If the hCG levels are less than 5 mIY then you are surely not pregnant and the delay of menses could be stress induced as in most women. You can then opt for a withdrawal bleed with Progesterones. The other most common causes of oligomenorrhoea are PCOS, hypothyroidism, and hyperprolactinemia. So you may get a hormonal profile to get these levels checked as well and an ultrasound pelvis to rule out polycystic ovaries which are again very common in young women.