Experiencing cramps, nausea, headache, and breast pain after ovulation could potentially be early signs of pregnancy. However, it's important to note that these symptoms can also be attributed to other factors such as hormonal changes or premenstrual syndrome (PMS). To determine if you are pregnant or not, the best course of action would be to take a home pregnancy test once you have missed your period. These tests are highly accurate and can provide you with a definitive answer. If you continue to experience these symptoms or have concerns about your health, it is recommended to consult with a healthcare professional for further evaluation and guidance.