Recognising the early signs of a possible fertility problem can lead to timely help, and this chapter sets out what to look for. It covers cycles shorter than 21 days or longer than 35, frequently missed periods and very light or heavy bleeding, as well as intense period pain that may suggest conditions such as endometriosis. Unexplained weight changes and symptoms linked to PCOS or thyroid issues are included, along with difficulties during sex. The second half explains the value of regular fertility check-ups, and of speaking to an expert even before you start trying, so you can receive personalised advice and a pregnancy programme.