Lower back pain, ovulating?

Hi ladies. I finished my first round of clomid 5 days ago. 100mg days 3-7. Today I'm experiencing back pain on my lower left. Glow predicted me to ovulate yesterday but all my opks are coming up faint. I got some cheap amazon ones and am wondering if they're just no good. But this pain, could it mean I'm ovulating or maybe in the next day or so?