Ovulation occurs when the ovary releases a mature egg into the fallopian tube in hopes of becoming fertilized by sperm. This occurs about 14 days before her menses is due to start. For women there are obvious signs when she is ovulating. Her basal temperature is greater, her cervical mucus is thicker she may experience some lower abdominal pain. There is another sign a woman is ovulating which is less obvious. According to research, a woman smells the most pleasant during ovulation. Now it isn't a dramatic change of smell or very overt but it is noticeable. One such research study was done by the Association of Psychological Science in 2009. This survey was done with men. One group was giving shirts worn by women during their cycle and another group was given shirts by women ovulating. It was concluded that the women who were ovulating raised the testosterone of the subjects simply by smelling their shirts. This is due to estrogen. The levels rise during ovulation.