Hi, thanks for using healthcare magic Premenstrual symptoms can occur as part of the menstrual cycle. In some women they are mild and do not impact on their life significantly, in others there can be a significant impact. In this case the person may have premenstrual syndrome. It is possible that increased urinary frequency and thrush are all related to the hormonal changes that occur when the period is about to start. During this time there is fluid retention and also mild uterine enlargement, both of these could possible result in the frequency you experience. It should not, however cause burning. This is usually an indicator of infection or can occur if there are cuts or lesions in the vaginal area. In terms of the thrush, many women experience vaginal thrush with or before their period though it is usually vaginal however everyone s body reacts differently to hormonal changes. If this pattern occurs with you then you can consider the use of anti fungal powders which would treat the thrush and have a drying effect. I hope this helps