We have received your tax return and it is being reviewed

Hello,

I filed my taxes and amended them the very next day as I realized I skipped one of the 1099 forms. The amendment increased my refund by $2. My refund status says “your return is received and is being reviewed”. Is my return being reviewed because I filed an amendment? Should I be concerned about further delay in receiving my refund or being audited, since the return is being reviewed? When can I expect my refund if my status shows being reviewed? Thank you in advance for answering my question.