Sometimes we suggest late tests more for the peace of mind of the concerned, not for the fear their test was inconclusive.
You used a certified product and should be trusted after the window period.
Was this done in a clinic or hospital setting?
They should have informed you that your test was conclusive.
The rapid blood test by clearview stat pak states in the DOCs, if you had no risk in the prior 3 months of using this product and you test negative, your results are conclusive and you do not have HIV.
This proves the reliability of certified rapid blood tests.
Need more?
http://www.medhelp.org/posts/HIV---Prevention/8-Week-Negative-with-Clearview-HIV-Stat-Pak/show/1841932
As RubyWitch said, "You obviously have some doubts, so for your peace of mind, get a lab test."
If you still have doubts, have a professional blood draw.
This is over 2 yrs ago and it still concerns you.