Hello,
As you were not involved in sexual intercourse since December, then reasons for delayed period may be hormonal imbalance, stress/ anxiety/ mental upset, 
ovarian cyst, irregular diet pattern, over wt or extreme loss, 
thyroid disorder etc.
Need to investigate properly to rule out underlying pathology by USG lower abdomen, Thyroid profile, LH/FSH, blood sugar & prolactin level etc
Curd like 
vaginal discharge with itching is mostly suggestive of yeast infection. One vaginal swab test is needed to confirm the diagnosis.
Here, you need to consult with your gynecologist for proper guidance through investigation & medication for delayed period.
Maintain genital hygiene properly. Oral anti 
fungal medication with vaginal suppository is very much helpful to eliminate yeast infection.
Avoid stress by regular deep breathing, take healthy diet with 
iron supplements, keep bowel habit regular, control body wt by regular exercise/ yoga and take proper sleep.
Be well & take care.