hello there.
it's not necessary that you have received your uncle's blood only.
normally what happens is, if you want blood, you would have to donate one packet of blood to the Blood bank and for that 1 packet, you would receive an already tested and stored blood which was there already.
so its not possible that you have received your uncle's blood.
and moreover, if your uncle's blood tested positive for
hiv, then the Blood bank would immediately safely discard the Blood.
so you can be tension free, you won't have hiv.
but if you still want to be sure. get yourself tested by a lab.
get the test done twice 3 months apart.
if both are negative, then you don't have to worry.
regards