Hi As you have mentioned there is irregularity in your menstrual period. One of the reason for it as you know may be the pregnancy. If your doctor has ruled out pregnancy by blood test or urine test then there may be some other problem which can cause irregularity in menstrual period. One of this reason may be recent miscarriage as in your case. Other reasons are Sever emotional stress can lead to irregular menstrual cycles. If you are anxious, worried or fatigued then you are more likely to have an irregular period. Being overweight and underweight are other possible causes of missed or irregular periods. Expert suggests that excessive weight is found to have adverse interference in menstrual rhythm. Eating disorders such as bulimia and anorexia are often linked to irregular periods. So if you have any kind of eating disorder then you are more likely to have an irregular menstrual cycle. Exercises that strain your body also disrupt the menstrual pattern. Poor nutrition disbalances the hormonal level and finally the periods. Tab. susten is a hormonal preparation. containing progesterone. it is used to regularize the menstural periods. Tab. Folic acid is used in early pregnancy and it is necessary for normal foetal development. It is also used to treat anemia. Hope you have got answers of your queries. Have a nice day Best regards Dr.Ehsan