Hi Scaredhuman, 3 negative results all outside of the window period are extremely reliable as by 12 weeks antibodies would be present if you were to have been infected. The only medication that is known to delay antibody production is PEP and PrEP which are types of HIV prevention. If you were to have been exposed to HIV 12 weeks prior to testing, the test line would be visible and most likely red/pinkish in colour. It is sometimes possible to see a shadow where the test line is pre-sprayed onto the strip but this is nothing to worry about. Your negative results are accurate and conclusive and you do not need to retest. I hope this helps. Kindest regards, The BioSure team.

Also would the test line be very visible if I were to be positive? On the second test I could see the faintest shadow when the test was lying down (the shadow wasn’t there at the 15min whilst it was standing up) and so I took another one at exactly 15 weeks and this one didn’t have a shadow where the test line would be (this was confirmed by your WhatsApp chat to be negative). Could the line have been missed?