Hi, Welcome to Health care magic forum.
The reasons for the delay in the period in general are
anemia, and infection. You have started a new brand of the
contraceptive pills, it may be the cause of the delay.
The cause if loss of apitite,mood swings,crying,light cramps, may be due to the new pills.
I advise you to consult your gynecologist for diagnosis and treatment.
Take more of green leafy vegetables, pulses, sprouts, and protein rich foods to correct anemia, and the develop resistance.
wishing for a quick and complete recovery. Thank you.