Hello,
First of all, I would suggest you to get your serum HCG levels estimated since this is more specific than urine for pregnancy tests. Apart from pregnancy, there are many other reasons for a delayed period. The other causes are hormonal imbalance like due to birth control pills, PCOS (Polycystic ovarian syndrome), stress, obesity, malnutrition, anemia, hypothyroidism, illness, etc. If pregnancy is ruled out then these causes should be evaluated.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
There is a slight possibility you may be pregnant. You might have to wait another week or 2 for it to show up on a urine test. Also if you have been extremely stressed out, this may also be causing you to be late for your cycle.