Help please !!!!

Yonce

My Ovia app is correct every month ! It says I’m supposed to start AF tomorrow, but Glow says next week. I have a cycle every 26 or 27 days every month ! I think Glow may be off, but my Clearblue Ovulation Test said I ovulated on the 3rd ! I have been getting a little blood when I wipe the last few days . Is this a light period ? Or what ? Please help !!!!