It is possible that you could be pregnant, especially if you are experiencing missed periods along with other symptoms such as abdominal pain and breast tenderness. However, the only way to confirm a pregnancy is by taking a pregnancy test. Waiting for 40 days after your last period is a reasonable timeframe to take the test, as it allows enough time for accurate results. Pregnancy tests work by detecting the presence of human chorionic gonadotropin (hCG) hormone in your urine or blood, which is produced during pregnancy. If you are indeed pregnant, the hCG levels will increase over time and can be detected by the test. It's important to note that there can be other reasons for missed periods and similar symptoms, such as hormonal imbalances or stress. If your test comes back negative but you continue to experience concerning symptoms or miss more periods, it would be advisable to consult with a healthcare professional for further evaluation and guidance.