Periods can be missed due to different reasons such as stress, hormonal imbalance, or pregnancy. Flustered, it's all right. The medicine you're taking helps to restore periods, and that's what your doctor provided. Simply do what your doctor has said, wait for the instructed time, and take the pregnancy test. 

Usually delay in period with sore breast is a symptomp of pregnancy. But certain matters as stress or hormone disorders or even thyroid diseases may result in late periods. Consult with your gynecologist

Periods occur when a girl reaches puberty. Sometimes, the periods can be irregular or painful. This may be because of stress, a poor diet, lack of sleep, or health problems. For example, some of the things she can do are eating well, exercising, and learning to relax. The excruciating discomfort can be unbearable without a doctor's advice.

There can be several reasons why your period flow may be decreasing at the age of 22. While it's normal for menstrual flow to vary from person to person, few reasons like hormonal changes, birth control methods, medications, etc. can affect menstruation.

You may have vaginal infection, which manifests in the form of itching and white discharge. It is advisable to see a gynecologist that will identify and manage your condition in an amicable way. Also, it is recommended not to use any aggressive soaps or perfumes at the genital and follow good hygiene rules.