Someone’s approached his Rosh Yeshiva, Reb Yehuda Zev Segal zt’l of Manchester, and said, “As the Rosh Yeshiva knows, my father was recently niftar. My mother requests that I leave the yeshiva to run my father’s food factory, so I can support the family.” Reb Yehudah Zev replied, “You should certainly help your mother, the almanah. I have only one request from you: every day, by Maariv, when you say ‘al nisecha shebechal yom imanu – the miracles that You perform for us each day,’ I want you to stop at these words and ask yourself, ‘what miracle did Hakadosh Baruch Hu do with me today…?”
This man says that he has followed his Rosh Yeshiva’s counsel for forty years now, and he can testify that there has never been a day where he hasn’t experienced a miracle. ~ R’ Elimelech Biderman Shlita

Are you allowed to stop in the middle of the Amidah for such thoughts?
I am not a poseik, but I certainly don’t think there are any problems with having such thoughts in mind. In fact, I think that is what we are supposed to do when we daven.