Relentless lower back ache

𝙲𝚊

I’m 32w3d and have had a lower back ache all day long. I’ve taken Tylenol for it and it didn’t do anything. It’s not consistent, it comes in waves; it’ll hurt for a few minutes, go away for a few minutes and then come right back. I tried taking a hot shower and just let the water hit my back and it seemed to help ease the pain once I could get the water hot enough but I didn’t want my body temp to rise too much, it didn’t make it go away. I still have it right now and I’m just wondering what it could be...