Based on the information provided, it is difficult to determine with certainty whether you are pregnant or not. The beta HCG test you took on March 16th showed a level of 53.4 mIU/mL, which could indicate pregnancy. However, the negative result from the urine test on March 19th raises some doubts.
It's important to note that HCG levels can vary widely among individuals and may not always be an accurate indicator of pregnancy. In early pregnancy, HCG levels typically double every two to three days. Therefore, it would be helpful to repeat the beta HCG test after a few days to see if there is any significant increase in the hormone levels.
Additionally, it's worth considering other factors that could affect your menstrual cycle and hormone levels such as stress, hormonal imbalances, or certain medications.
To get a definitive answer about your pregnancy status and ensure accurate interpretation of your test results, it is recommended to consult with a healthcare professional who can perform further tests and provide appropriate guidance based on your specific situation.
Remember that every individual's experience with pregnancy can vary greatly, so it's essential to seek personalized medical advice for accurate information and support during this time.