Not being taxed on paychecks

I updated my w4 to HOH with 3 dependents.  This is how I file my taxes every year . All dependents are under 17. I noticed no federal taxes have been taken out of my last 3 paychecks since the update . Will I owe federal at the end of the year.  I make around 52k to 55k. Just in that ballpark area.