First of all i would like to mention that periods get delayed many a times due to following reasons:
- hormone intake(in the form of tablets or patches)
When periods get delayed then pre menstrual pain
and cramps are enhanced till you get your menses.
As you have not visited a doctor then as a precaution i would recommend you to do pregnancy
tests every 15 days. If you do not get periods for more than a month after this then you must see a doctor.
He would do an ultra sound
to confirm if you are pregnant or not. Till then you can take mild muscle relaxants to ease the pain.