Look at the fare code on your ticket and then check the fare rules. While a U-UP fare is a theoretical possibility, if you had a cheap U fare, the upgrade and booking as A class might have been a mistake. In that case, you would not deserve/get the extra MQMs because you did not purchase an A fare or any other fare class that is eligible for the 150% MQMs.

An A class fare is likely to have the letters UP in the fare code and have a statement in the beginning of the fare rules that this is a FC fare but is valid for coach if FC inventory isn't available on the flight.