What are Antonio's thoughts after he guarantees a pound of his own flesh to Shylock if he does not repay his loan?

In Act I, Scene 3 of Shakespeare’s The Merchant of Venice, Antonio agrees to a preposterous proposal by the sneaky Shylock — that he pledge a pound of his own flesh as a guarantee if he can’t come up with Bassanio’s payment in three months. 

SHYLOCK: “…let the forfeit
Be nominated for an equal pound
Of your fair flesh, to be cut off and taken
In what part of your body pleaseth me.”

Confident he will have no problem securing the necessary amount, Antonio not only pledges a pound of his own flesh, but also states he will have the sum ready in two months.
After Shylock leaves, we see a note of sarcasm from Antonio:

The Hebrew [Shylock] will turn Christian: he grows kind.

Bassanio replies that he does not like the terms of this agreement, even calling Shylock a “villain”. 
Antonio, unfazed by the intense meaning of his deal with Shylock, consoles Bassanio with these words:

Come on: in this there can be no dismay;
My ships come home a month before the day.

Antonio is completely unruffled by Shylock’s severe demand, confident his ships will be prosperous and bear the money Antonio will need to pay back his loan. Even though his own flesh is on the line, Antonio is far calmer about the arrangement than Bassanio, even being so bold as to crack a joke about Shylock.
http://shakespeare.mit.edu/merchant/full.html

https://www.playshakespeare.com/merchant-of-venice/synopsis