You also have to ask yourself if either of your cards hit will that give you the best hand.
Example if the board shows all low cards and a 4 flush on the turn - he might be betting top pair especially if he bet so small like that he doesn't want to get reraised and having to dump the hand. If you had AcKh and the 4 flush is clubs and you have the ace of clubs, but the next highest card on the board is a 10 or similar if you hit your A or K will that give you the best hand? It's a tuff call on the river if you hit an ace or K, but he bets the pot. Is he betting to try and get you to fold your 4 flush, bluffing
, or does he already have a flush? You have to know a little more about him to call here.
The other thing to think about is how big is your flush draw? Is it big enough that if you make your flush draw you'll beat his possible flush or flush draw? Did he bet that much because he has the ace of clubs and think your on the same flush draw so he prices you in on purpose hoping for another club to hit giving him the nut flush vs. your 2nd best hand.
I'm just saying all this because you should think of more than just pot odds