11 Days til AF

Okay so I've been trying to keep track of my cycles. Around September they got a bit earlier. So af can show anywhere from 23-25 days for me.

This current cycle based off of Glow my fertile days were Oct. 22-28th. I had bd 5 days within the fertile week.

Af is expected in about 10-11 days from now. The thing is... I'm cramping really bad(which nor.ally happens 2-3 days before af shows). Could this cramping be due to implantation or af coming earlier than expected? Thanks Ladies!