The usage of piggybacking
From my comprehension, I am able to piggyback on previous conversation of a friend. Is it possible to piggybacking on my previous answer? Let me describe a scenario. Someone asks me a question and I provided him/her with an answer. Subsequently, that person asks me a second question. Can I say 'I am piggy-backing' on my previous answer. There is extra info that I would like to add in regard to that...'

Question

The usage of piggybacking
From my comprehension, I am able to piggyback on previous  conversation of a friend.  Is it possible to piggybacking on my previous answer? Let me describe a scenario. Someone asks me a question and I provided him/her with an answer. Subsequently, that person asks me a second question. Can I say 'I am piggy-backing' on my previous answer. There is extra info that I would like to add in regard to that...'

Answer

Because "piggybacking " means to " get on another person's back", you would best use it when you piggyback on someone else's answer.

Answer

To piggyback, in this case, is to use an existing thing (in your case, an answer) as support.

I wouldn't call it a foul if you said 'I am piggybacking on my previous answer,' but I will say it sounds a little odd (because I don't hear it often.)

I would say something around the lines of, "Referring to my previous answer, there is extra info I would like to add."