No, you may not file as head of household because you weren't legally separated from your spouse or considered unmarried at the end of the tax year. To be considered unmarried at the end of a tax year, your spouse may not be a member of your household during the last 6 months of the tax year and you must meet other requirements.

Your filing status for the year will be either married filing separately or married filing jointly.

• If you use the married filing separately filing status you can be treated as not married to claim the earned income tax credit. To qualify, the spouse claiming the earned income credit cannot file jointly with the other spouse, and satisfy certain other requirements (for example, not have the same principal residence as the other spouse for at least six months out of the year or have a written separation agreement and do not reside with their spouse at the end of the year), and must have a qualifying child living with them for more than half the year. You cannot claim the credit for childcare expenses since you were considered married. This credit requires married taxpayers to file a joint return to be eligible for the credit.
• You may be eligible to claim these credits if you decide to file a joint return with your spouse.

See What is My Filing Status? and Publication 501, Dependents, Standard Deduction and Filing Information for information about filing status.