I made $9,400 on a 10-99 last year. I have about $2,000 in expenses and I have two dependents. I paid $0 in federal tax...

I did my taxes through turbo tax and claimed head of household. Is it normal for them to take 80% of my return for the unpaid taxes throughout the year??  I thought it was only 15% ??? And every time I put in a deduction my return would go down. Help please!!!!