My period is kinda difficult to predict.. So the past 4 weeks, I've been starting around the 9th of each month... Before that I was starting around the 23rd.. So! This month, the 9th came around ¬hing showed so glow pushed it back to the 13th...now the 13th has came &NOTHING... not sure if I should wait til the end of the month or go ahead and test... ANY SUGGESTIONS???