Efrem

I understand, but:

(a) You are not the first air traveler to have had a double connection. Thousands of people do it every day. In fact, hundreds of people have three or more connections every day. The airlines have seen this before and know what to do.

(b) Nearly all of those thousands of people had his or her first double connection at some point in the past. They all survived the experience and are willing to do it again.

(c) Each connection stands on its own. Nobody is going to look at your bag at the second connection and say "this is her second connection today, let's put her bag on that other plane just for kicks." Having two of them doubles the chance of something going wrong, but that's a very small chance to begin with so twice that chance is still tiny. If you'd take a chance with one connection, there's no reason not to take a chance with two.

Enjoy Cuba!