After his raise the pot is $5.19. I'd probably reraise him another $9-$10 here. He will be doubtful you have the flush, since you raised preflop, which is typically "powercards".

My reasoning here would be that all-in basically means that he'll only call with a higher flush (since the pot vs the stacks difference is too big), while with a 2x pot raise you give him some incentive to call with a lesser hand, while at the same time giving a possible chase with Ah very bad pot odds.

If he then pushes, you take it. If he calls, you push the turn no matter what. The only possible downside in this approach that I can see, as opposed to pushing all-in straight away, is that he can call with Ah and hit his 1/6 chance to see the heart on the turn. Regardless, he payed more than the odds gave him chance anyway, and the benefit here is that he will be a lot more inclined to accept with something like a set. This means on average you should make more money doing it this way.

(the case that he has Ah or Kh or whatever, seems a bit unlikely.. he would call in that case probably, not reraise you on the flop. It seems more like he has hit something strong like a set, or he has overpair, and wants to get YOU off of a possible perceived chase. So you probably win; hence I'd build up the all-in with a 2x pot reraise first)