New to the forums, so please advise if this is not the place for this type of post.

PokerStars 2NL (6-max) Stacks: $1.66 eff
My hand A5 in BB

BTN raises to 0.05, SB (villain) calls, I call in BB

Flop: A J 5

Villain and I check to PFR, checks through

Turn: 8

V checks, I bet 0.09 (into pot of 0.15), BTN folds, V calls.

River: 9

V leads for 0.32 (pot size), I call and loose to 107

For those who play the micros a lot, is this lead on the river, very telling of a "nut" hand, or did I make the correct call?
I think he could easily be betting with a missed flush draws as a bluff or even a lower value hand (J-8, J-9), but he could also have 8-8, 9-9 or 10-7s.

Any help would be greatly appreciated, or if someone could point me in the direction of a online tool or program that would help me analyze this.

His pot sized lead into the river def feels strong. I doubt he would play 55 or 88 this passive since the boards kind of wet and he could get more value out of Ax type hands, so I'm not worried about a set.
So, his range is pretty much split between busted flush draws and lower 2pairs, but occasionally A9. The gut shot he hit is a small enough part of his range I believe to justify the call, because much more often ur gonna see two clubs or 89 or J9. If u wanted more exact math u could count the exaxt # of combos for all his potential hands, but winging it I'm pretty sure 1:1 is good enough in this spot

Welcome, yes this is the correct place.
I'd bet bigger OTT and call OTR with all the obvious draws missing and our hand beats some of their value range. It's impossible to assign a range on the river donk as it varies so much between villains so we need thousands of hands.

No-one can give a blanket answer "Oh this is always a bluff", just look at the board and see if any obvious draws come in and overfold a ton if the answer is yes. As you play more, take note in general what % is value/bluff.

For tools, look up pokertracker4 and flopzilla. They should help your game + thinking towards these spots.

It's fine.

2NL simplifies to bet when you have it, check when you don't. Just donk for value the flop. You will get called by tons of hands.

Thanks you all of the help!