My period is 3 days late when should I do a pregnancy test?

I had my daughter 9months ago today. Since Ive had her Ive had my period pertty regularly. Every 28 days expect now. Im 3 days. Im going to be excited if I am. My husband and I trying but I just want to know when should I test. How long should I wait. I tested last week and yesterday and it was negative. So Im just curious :) Im having all the symptoms and Ive compared it to infection symptons and diabetic symptoms and ovarian cyst symptoms the only thing that doesnt match with the infection, diabetic and ovarian cyst symptoms are incease breast size, increased libido(sex drive).