Walmart Overnight Stocker interview questions

I got hired to the job very quickly. I applied online and soon enough I called the next week and they told me I could come in for an interview the same day. No resume needed or any information other than to pass the drug test. Very straightforward and it is most like everyone gets hired if they at least show decency.

Applied online 9-9-2016 got a call to come for a interview.9-13 Got a call 2 days later to come in to accept the job offer awaiting for background check since 9-15-16.it's been 2 actual week and 8 business days called and said it's still pending..hoping everything is ok I'm so anxious why the background check is taking so long any one else experience this before?