How To Confirm Pregnancy After A Missed Periods?

hello. My periods are regular my last period was on 17th feb 2015 was expecting my periods on 17th march 2015. Its 18th march and havent got my period yet..today morning i took I sure pregnancy test it waa negative. Is there any chance of mine to be pregnant? Or should i take a blood test this early or wait? We planning for a baby. Please help.