Tracking follicle stimulating hormone (FSH) levels over time can give you insight into your ovarian reserve (your remaining egg supply) if you are trying to conceive. FSH levels increase temporarily at the beginning of each cycle to stimulate your ovaries to produce eggs. When your ovarian reserve is lower, more FSH is required to stimulate them. By providing insight into ovarian reserve, testing FSH can help you make a plan and get set up for success.