Technically, "No". If you received a W-2 it is not treated as self-employment income - even if you were your own boss.
Your employer (the S-Corp) would have paid the employer's share of your employment taxes (Social Security & Medicare) and withheld your share for remittance to the IRS. The S-Corp would probably also withheld federal tax from you W-2 income, and remitted that to the IRS as well.
