Need my anxiety decreased! 5 weeks and have Back pain

I am 5 weeks tomorrow and things are fine no spotting or bleeding but I had my levels check and they are doubling so doctor is happy he is sending me for ultrasound in 2 weeks! So I have gotten no bad news but I have had a miscarriage before and a blighted ovum I am having some lower back pains so I am freaking out just a bit but I guess my question is anyone else have lower back pain!?