Unsure when to expect my period

Bekah • BFP 03.03.15 MC 04.07.15 BFP#2 04.08.16 -praying for our Rainbow; all while working in a daycare
Glow has my period coming this Saturday (which would put me back to my normal timings) 
But FF says that it will be here on Wednesday(which is what it has changed to these last few periods). 
Just wondering what you ladies think.