The menstrual cycle for each woman can be different. The normal menstrual cycle ranges from 21-35 days. From the circumstances that you experience, if you usually have a menstrual cycle of 18 days then it means you have a menstrual cycle that is too fast.
Some conditions that can cause abnormal menstrual cycles, such as:
the effect of family planning (if you use family planning) excessive stress. Impaired hormone levels, ovarian cysts, myoma uteri. If you take vitamin E supplements, this vitamin cannot actually change / improve the menstrual cycle. Vitamin E does not have a function in regulating the menstrual cycle. Maybe the drugs you are taking have hormonal content, drugs that contain hormonal agents can usually improve irregular menstrual cycles. However, the use of drugs that contain hormones should be prescribed by a doctor so that the dosage and type of drug are correct.
Therefore, to determine the cause of the condition you are experiencing, then you should check with a gynecologist directly, so that the doctor can check your condition directly and provide the right therapy for you. Maybe later an ultrasound examination will be done.
It is recommended that you do not stress excessively. Eat nutritious foods. Get enough rest, and don't smoke. Regular exercise can also help.
Here is an article that you can read about menstrual smoothing drinks
may be useful. Thank you