Hi Help2 Thanks for getting in touch. You have taken a really important and empowering choice. The test is extremely accurate when testing more than 3 months after possible exposure and negative results will be correct more than 999 times in a 1000. The control line is there to show that you have performed your test correctly. It will only trigger if you have applied enough sample and buffer. There is approximately 3 times as much buffer in the pot than is required to run the test, so even if the test is not pushed down completely it may well still run. If your test hadn't absorbed enough buffer the control line wouldn't have come up. All in all you can rely on your negative result. I would not recommend retesting. I hope I've answered your questions. Kind regards Gary Carpenter BioSure (UK) Limited