Really sore back😢

Lauren • 31, partner is 35. We have three children, William 10, Georgia 2 & Eliza just born. I work with domestic abuse victims in the north east of England. Partner is a roofer/joiner.
I am currently cd17. My app says i ovulated yesterday. But my temp spiked on cd12 so I'm thinking I am either 5dpo or 1dpo. Anyway, today my back is so sore. Like as if I have an infection. But I doubt I do have an infection. And my abdo feels heavy. Can this happen during OV?! X