I got my set, but on a 3-flush flop

[guppy]

Texas Hold'em No Limit (£0.50/£1)

I have the button, with about £50. The whole table has me covered.

I am dealt a pair of 6s.

6 limpers in front of me, I limp too, as do the blinds.

Flop is 9h 6h 7h. Hooray! I got my set!

But I could be losing to a straight or a flush. If I'm winning, there could easily be both straight and flush draws out there. OTOH, if I am losing, or get outdrawn, I have a redraw to a full house.

Flop action: A token £1 bet and 3 calls to me. Pot is about £13. I have the short stack of roughly £50. I should ...?

What I did (and results) in white:
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I pushed. I got one caller. He had flopped the straight flush.
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