Fever at implantation?

I am CD 18, DPO 6. This is my first month tracking with Glow. I previously used a different app and previously had not been watching my BBT. Has anyone else experienced a fever on the implantation day? I don't feel sick but my temp first thing was up by 0.8 since yesterday and the past few days. Not sure if it is related to implantation but we really want to get pregnant.
​Also, for the last 30 minutes or so, had really dull period like cramps. Does that mean more to anyone? Thanks!