I'm on cycle day 22, AF due next week (5/9) and I had a positive OPK 10 days ago. Today I'm experiencing what almost feels like the early phases of my menstrual cramps...light cramping, chills, slight nausea, and a general tired/out of sorts feeling. I'm confused because AF isn't due for another 5 days (and she's never early, if anything she's a few days late most cycles) and normally I don't have these symptoms until immediately before my period. Has anyone experienced something like this? It's just the timing of the symptoms that is throwing me off. I'm wondering if it could be symptoms of implantation (fingers crossed), but Glow says I'm still 4 days from taking a pregnancy test.