First up defining stress. Stress is actually what we go through everyday, it's like the definition of challenge. For us people stress is what we don't want but is the essential thing of forming us. For plants experiencing stress just like malnutrition they are slow to bloom and make their fruits.
After your period is due and has passed after 5 days then check again or take a urine test.
c) ask for help
They should realize they will need to ask for help
Ask questions to to the doctor and get more informed