The cycle of menstrual periods repeats in around 21-35 days normally and if your periods are coming between that then your reproductive system is quite healthy but in case there is imbalance in that cycle like you bleed before 21 days or missing periods even after 35-40 days then you would need ayurvedic treatment for irregular periods. Once a while dealing with irregularity in periods is quite common but if it is bothering you very often then something must be done to make a deal with that. Sometimes the problem can be due to another health problem like diabetes, obesity or fluctuation in hormones but yoga postures can work in you favour. So, you can try the following mentioned yoga postures:
Triangle Pose (Trikonasana)- In this yoga pose, you should stand sideways bending and thus it gives way to stimulation of reproductive organs. In females especially it works great for uterus and ovaries because any of the problems regarding the same would end in menstrual issues. To try the posture you should stand straight with keeping the legs a couple feet apart. Now, turn the right leg at the right angles to your body. Now, slowly bend sideways and here you should bend till the hands would touch the floor. Now, raise the left hand straight in upside and try to fix the gaze upwards towards the hand that is raised. Hold posture for 4-5 minutes and then slowly come back to normal and then repeat the same with another side. These asana has great power to deal with issue and can also the support if you are already taking ayurvedic treatment for irregular periods.
Mountain Pose (Tadasana)- The name would have given you an idea that this yoga pose is extremely tough but in opposite to that it is an simple standing yoga which works great for stimulation of reproductive organs and brain centres and in short make a control over the irregular menstrual periods. To try the pose, you need to stand straight and keep the legs straight. Keep your feet slightly apart and stare towards the front. Now, you should raise the arms above the head like Indian salutation pose and keep feet flat on ground and stand on the toes. Hold for 10 counts and then relax.