Yes you might have heard this,it was about 20 years ago in the early 90s,the tests are better now--it doesn't happen anymore--relax now please,you're safe.
Because I have heard people test positive after 13 weeks. Isn't everyone's immune system different?
How can it become positive in the future when you tested negative at 12 weeks?It can't unless you have another risk that is.
Only if you give me your lotto numbers :). Its really worrying does HIV status mean status as in the present time and HIV infection can become positive in the future ?
You got very lucky--your test for HIV at 12 weeks was negative--you don't have HIV.Go and buy a lottery ticket.