Prego?

Renae
So according to the app my fertility period was the 7-13 I had sex on the 6&7 and has spotting on the 8th I have a period every 2 weeks since my daughter was born in august. And it's always the day it is supposed to happen never been late. I'm also on BC pill. I am a day late what's the possibility I could be pregnant please and thank you