Help: Ovulation days & pain

Hi ladies, 
According to glow I started my ovulation phase about 3 days ago and since wednesday I've been having left lower back/side pain. It varies from pretty bad to achey. I'm not sure if this is caused by my body ovulating or something else. I originally thought it might be a kidney infection, but I have no other symptoms (urinary urgency/burning/odor). 
I know to get the best info I should see my doctor but they are closed for the holiday, so I wanted to ask if anyone else had experienced something like this and what the cause ended up being? 
Thanks so much!