When should I test again???

Mandy
So I tested on the 30th (because Glow told me to) and got an obvious negative. I was supposed to start my period today but she was a no show and no symptoms at all (I usually have symptoms by now) my last period was a spotting for about 3-4 days. Anyways it is supposed to be the second day of AF and she isn't here still should I already test again???? I'm scared of those nasty BFN