Issue when querying pinecone data

Question

Trying out a simple application with Langchain and Pinecone training by uploading a PDF document. I was able to upload the vectors to pinecone successfully but whenever I try querying I receive a PineconeApiAttributeError: QueryResponse has no attribute '0' at ['['received_data']'] error. The query was in string format and was embedded in vector format using OpenAIEmbeddings(). My code is as follows.

def retrieve_query(query,k=2):
    xq = embeddings.embed_query(query) #embeddings = OpenAIEmbeddings(api_key)
    matching_results = index_name.query(vector = xq,top_k=k,include_values=True)
    return matching_results 
from langchain.chains.question_answering import load_qa_chain
from langchain import OpenAI
llm=OpenAI(model_name="text-davinci-003",temperature=0.5)
chain=load_qa_chain(llm,chain_type="stuff")
def retrieve_answers(query):
    doc_search=retrieve_query(query)
    print(doc_search)
    response=chain.run(input_documents=doc_search,question=query)
    return response

the doc_search variable printed out {'matches': [], 'namespace': '', 'usage': {'read_units': 6}}