You need to buy a BBT thermometre, and then take your temp at the same time every morning when you wake up, before doing anything else. Do not speak or drink or move about. You should try to get atleast three full hours of sleep before taking your temp. I think you are OK to take your temp within the same hour every day, I take it between 5 and 6am. Then plot it in fertility friend (click on mine and register) and enter your temp every day. Also note your cm, as that is a big sign as to when you are about to ovulate