BBT rise right after period?

Erin

I just had my first postpartum period since having my daughter nine months ago. My period ended 4 days ago, and since it ended my bbt has spiked. From 95.01 the last day of my period to 95.91 this morning 4 days later. I have had no signs of ovulation or anything and am confused as to why I would be seeing a temp spike after my period?