i would say it would be good to do a pregnancy
test you can conceive without feeling any symptoms
the fact that she has taken the pill quite often in month of jan it could be the reason for the delayed periods as these are hormone based.
other causes need to also be rulled out like any masses in the uterus
,ovarian cysts hormone imbalance
i would suggest get a review done by a gynecologist to know what is going on
hope have answered your query