Stop beating yourself up! Oh, if only we had a crystal ball, life would be so much easier wouldn't it? How were you to know this would all work out? I am impressed that you took a pro-active approach to this situation.
Honestly, it's better that it happened this way than to have everything fall apart two days before you were supposed to leave, right? :)
Send your husband lots of texts and let him know that you miss him and are thinking of him. And for you: enjoy some "down time" with just you and your son. When my husband travels, we do all the things that he doesn't like to do- eat at certain restaurants, watch silly videos- you get the idea!