26 Weeks: Cramping + Lower Back Ache

Before anyone says to call my doctor, I fully plan to if it’s not better by tomorrow I just want to know if I’m overreacting or overthinking.

This is my first baby and I’m 26 weeks today. Yesterday at work we were pricing things (heavy things that I wasn’t lifting but had to pull out of the box) and my back started hurting and I started cramping. I thought maybe it was partly gas or constipation. This morning I woke up and I felt better for the most part but I’m at work and it’s happening again and this time I’ll get sharp pains along with the cramps every so often. And my lower back hurts a lot. Sitting on my break helped a bit but it still hurts. Could I be feeling like Braxton Hicks contractions (I have no clue what anything feels like) or should I call my OB today instead of waiting to see if it’s better tomorrow? Thank you for the help ❤️ I’m trying not to worry because I know it’s probably nothing but I want to be safe.