Another unclear 6-max hand

[PoBoy321]

I've been at the table a while but BB is new, so no reads.

Ultimate Bet No-Limit Hold'em, $.10 BB (3 handed) FTR converter on zerodivide.cx

Hero ($19.41)
SB ($10.09)
BB ($9.65)

Preflop: Hero is Button with A[img]/images/graemlins/diamond.gif[/img], Q[img]/images/graemlins/heart.gif[/img].
<font color="#CC3333">Hero raises to $0.5</font>, <font color="#666666">1 fold</font>, BB calls $0.40.

Flop: ($1.05) Q[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/club.gif[/img], 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets $0.9</font>, BB calls $0.90.

Turn: ($2.85) 5[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, Hero checks.

River: ($2.85) 3[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">BB bets $0.45</font>, Hero calls $0.45.

Final Pot: $3.75

Is this a raise on the river? Also, what do you think about my turn check? I was hoping to keep the pot manageable against a K and hopefully induce a bluff from a worse hand on the river.