anyone else expecting AF on the 25th? support thread :-)

I'm currently on CD 19, my <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> says AF should be here on the 25th but my FF app says the 23rd, anyone else on here due around that time? when is the best time to test? baby dust to all!