Why would a urine test come out positive before taking and negative after antibiotics for bladder infection when you are on Mircette Birth Control started your period week ago?

Several reasons could explain why your urine test results may have initially shown a positive result for a bladder infection before taking antibiotics and then a negative result after completing the antibiotic course while on Mircette birth control and having your period about a week ago. Here are a few possible reasons:

Antibiotics' Effect on Bacteria: Urinary tract infections (UTIs), including bladder infections, are commonly caused by bacterial infections. When you started taking antibiotics, the medication would target and eliminate the bacteria responsible for the infection. As the bacteria is cleared from your urinary system, the infection's symptoms, including the presence of bacteria in your urine, would diminish.

Urinary Tract Cleansing Effect: Antibiotics can have a cleansing effect on the urinary tract, removing bacteria and other potential contaminants. As the antibiotics flush out the bacteria from the bladder and urethra, the urine may become clearer, leading to a negative result on the urine test.

Timing of Urine Collection: The timing of urine collection can influence the test results. If you provided a urine sample shortly after starting antibiotics, there may have been a significant reduction in bacteria, resulting in a negative test result. On the other hand, if the sample was collected before starting antibiotics, it might have captured the presence of bacteria, leading to a positive result.

Menstrual Cycle Effects: Hormonal changes during the menstrual cycle can impact the urinary tract's environment and the presence of bacteria. Since you mentioned being on Mircette birth control and having your period a week ago, it's possible that hormonal changes or other factors related to menstruation could have influenced the urine test results.

Test Sensitivity and Specificity: The sensitivity and specificity of the urine test can also play a role in the results. Some tests may be more sensitive in detecting specific bacteria, while others may be more prone to false positives or negatives. The accuracy of the urine test depends on various factors, including the type of test used and the concentration of bacteria present.

It's important to note that interpreting urine test results should be done in context with your medical history, symptoms, and other diagnostic tests. If you have any concerns or persistent symptoms, it's advisable to consult with your healthcare provider for further evaluation and guidance. They can provide the most accurate interpretation of your test results and recommend appropriate treatment or follow-up care if necessary.