Cervical mucus
Around ovulation, many people notice that vaginal discharge becomes clearer, wetter, slippery and stretchy, a bit like raw egg white. After ovulation it often becomes thicker again. Noticing these changes can help you get to know your own cycle.
Body temperature
Resting body temperature rises slightly after ovulation. This means a temperature chart can only show afterwards that ovulation probably happened. NICE guidance says temperature charts do not reliably predict ovulation and does not recommend them, as they can also add stress.
Other signs
Some people notice mild pain on one side, breast tenderness or changes in mood. These signs differ a lot between people and cycles, so they are not a reliable guide on their own.