Pregnant?? So confused!

According to Glow my peak fertilization day was Sunday the 31st. And according to them I was supposed to start my period on the 9th of this month. I woke up this morning and when I wiped there was blood...since then absolutely nothing. Not even a hint. I've been extremely tired lately but no other symptoms. Could that have been IB? I'm too nervous to test...I don't want to see another negative test result. What do you ladies think?