Back pain and eggwhite cm... what does it mean?

So I just got off my af on the 22nd, the very next day, I had a lot of clear, slippery, stretchy, eggwhite cm. I thought it was strange because theres no way I could be ovulating immediately after my af, right? And then, out of nowhere, late that day my lower back starts hurting. It's an aggressive, dull pain. Both the back pain and eggwhite cm have been consistent over the past 3 days. What does it mean? Does anyone have any idea? Have any of you ever had similar symptoms?