Lower Back Pain

I’m having extreme anxiety. I’m pregnant for the 5th time, I’ve had 4 loses. I am with a specialist & have seen a gestational sac & yolk sac at 5w1d. I am 5w6d now & won’t be seen again until 7w1d. My lower back is bothering me from hip to hip but main pain is dead center of my lower back. Is this normal? I experienced it with all of my loses (including cramping which I’ve only had mildly this time.) but my anxiety is getting the worse of me. *this is the first time I’ve seen a sac with a yolk sac*, my first two I miscarried before we made it to the doctor appts, third was an ectopic, & fourth was an empty gestational sac & levels didn’t rise properly. So it is good news but just worried & looking for reassurance.. 🥺