Hello, thanks for the query. Regesterone tablet contains norethisterone to regulate your menstrual cycle. Once your cycle is regularized then chances of conception increases. Side effects include breakthrough bleeding, breast changes, including breast discomfort, feeling sick , stomach ache, appetite changes, headache, dizziness, depression, drowsiness, tiredness, sleeplessness. I recommend you to carry on with your doctor s prescription. Start taking preconceptional folic acid as well. Hope this helps, regards, Dr Nilofer