Hello there, thanks for writing in. If your periods problem is a long term issue it could be due to hormonal imbalance caused by excess male hormones and it is broadly called polycystic ovarian syndrome and I suggest you do meet your doctor for its evaluation at least once as it has long term health implications like diabetes, heart disease etc. But if it just for once that your periods are delayed, I would say it is nothing to worry about and the slimy odourless discharge you are experiencing is normal cervical ( neck of the womb ) secretions that increase under the influence of estrogen secreted by developing egg and the day of maximum discharge indicates ovulation and you can expect your periods two weeks later. The changes are probably due to the effect of exercise which is thought to improve metabolic profile ( ability to handle glucose ) and hence a good ovulatory cycle ( both are inter linked ). Hope this information is convincing. Take care.