Late on my period

Christina • Engaged to the love of my life and enjoying life with our little boy! ☺️☺️💙👶🏻

So me and my boyfriend have been TTC for about a little over a month and my period was suppose to start on the 18th of February and now it’s the 20th and I still haven’t started nor am I spotting. So my question is how long should I wait before I take a pregnancy test? Please help!!