CD 52 I am retesting in the morning. I forgot to this morning lol. I am having strange pains in my…

CD 52 I am retesting in the morning. I forgot to this morning lol. I am having strange pains in my mid/upper back when I have to go #2. The pain is relived as soon as I go. I have never experienced this before and my bm's are pretty regular. No constipation or anything so I have no idea what could be causing this weird pain.