Laying an ugly beat

It looked like I laid an ugly beat on an opponent during the Brit game today. I don't think I did. I think they did it to themselves. A correct bet probably would have forced me to fold. Instead I end up having chips swooshed to my side.

I was just trying for the steal. A 8 spades from the button. I raised 3xs the blind. The SB min-raised me. A min raise? I will call that and see if I get lucky on the flop.

Flop is J J Q, two spades. Not bad. Not good, but not bad either.

My opponent checked to me. My first thought was to make a bet, but then I stopped. That check seemed pretty suspicious. Why did he check there? If I bet I will probably get raised. This doesn't feel good so I check behind.

Turn is an A.

Hmm... that kind of traps me in this hand. If my opponent is playing ace rag too, it will most likely be a split pot. Can I fold here? I still think he has a monster. Making my flush could be a bad thing. He bets 60. 60 into a 600 pot? Still doesn't seem right but I can fold here. I call instead of making a move to put him all in.

River is another A. Only A Q can beat me now. He shoves. Can't fold here. I call to see he had pocket queens. Flopped a full house and let me stay around to draw out. A bet on the flop may not have had me folding, but a bigger bet on the turn, with me thinking he flopped a monster would have had me folding. Instead he got knocked out by slowplaying.