Why no periods at 21?

It happens rarely. May occur with long-term use.

Symptoms you may be experiencing can be due to hormonal changes, which may not be indicative of pregnancy. An irregular period can cause the hormone levels to fluctuate, leading to tender breasts, bloating, and mood swings. Stress, diet, and lack of exercise can also be the reasons why your body is affected this way. Try managing stress, eating healthy, and gentle exercise to help balance your hormones.

When stopping contrace­ptives, your body might take time adjusting be­fore pregnancy's possible. Irre­gular periods are normal for a bit. If avoiding pregnancy's de­sired, consider alternative­ birth control like condoms. 

Cramping is a common symptom of the menstrual cycle and can occur even if the period is delayed. If you are sexually active you must consider the possibility of pregnancy and take a pregnancy test to confirm. a gynecologist can evaluate so please take an appointment

Endometriosis is a situation where the tissue is growing outside its proper location and this leads to the formation of cysts and causes pain. Ayurvedic treatments can be used to shrink the 30x20mm cyst on your right ovary. To reduce manifestations such as discomfort and untimely monthly cycles, herbs such as turmeric and ashwagandha may be beneficial. In addition, following a healthy diet, practicing relaxation techniques, and doing light exercises such as yoga can be promoted.

Its better to get it confirmed with a pregnancy test. Based on the results you can take further prenatal care.