Hello
I appreciate your concern.
Delayed and scanty period warrants detailed evaluation by a gynaecogist to find out underlying cause for it.
I would advise you for a battery of investigation like CBC
ESR liver function test, blood sugar, urine culture and
ultrasound pelvis or
hormonal study if need be, to establish a diagnosis and subsequently it's treatment.
You need not to worry, Book an appointment with a gynaecogist as per your convenience for physical examination and all the investigation as I advised.
Meanwhile maintain good hygiene, wash your private parts with lukewarm water and antiseptic solution after sexual intercourse.
Have lots of fluids orally which will help by
flushing off the urogenital tract and clears the mild degree of infection.
Hope this answers your question please feel free to ask for further assistance I will be happy to help you.
Best wishes