Spotting 4 days after ovulation??

Doing our first cycle with Femara and a trigger shot. Today I’m 5 days post trigger and I believe 4 days post ovulation, I have been having nausea, sore breasts, and a headache for the past few days which I know if from the trigger shot . Today I woke up with cramping and pinching sensation in lower abdomen plus some light pink spotting this afternoon. I know it’s probably too early for implantation but why would I be spotting?? Anyone else ever experience this after a trigger shot?