It sounds like you could be suffering from a urinary tract infection
which has symptoms like:
-Burning micturation (urination)
-Reduced amount of urine passed
-Itching around genitalia
-Blood in urine (rare)
Although not all symptoms need to be present in one person. Infections are one of the most common cause of a delay in periods.
I would advise you to visit a doctor and get your urine analysed after which; if the infection is confirmed the doctor will treat you with antibiotics, pain management, and a urine alkalizer.
You should feel an improvement within 24-48 hours of initiation of antibiotic therapy if the appropriate antibiotic is initiated. Also in the meantime, please drink plenty of water and wear comfortable undergarments (clean and dry).
Hope this helps.