Persistent lower back pain

I am 8 weeks 2 days and I have had persistent lower left back pain probably since I found out I was pregnant at 4 weeks. It’s come and gone a few times but more so in beginning but the last 4 days it has been non stop. It’s driving me absolutely insane no way I lay/sit/stand relieves it and its freaking me out. My doctor keeps saying it’s normal and some people just have this in pregnancy but I didn’t have this with my first child at all. I have been getting weekly ultrasounds since I’m in fertility treatment but that ends next week as I’m being transferred to regular ob so I’ll be even more worried. I also have 3 hematomas as well in my uterus I was told to do pelvic rest and no using heating pad so im at a loss on what to do or if anyone else out there has expierienced this and had a healthy pregnancy