I'm 7wks 5days & i'm getting this dull achy lower pelvic pain for a couple days now accompanied by some back pain, no bleeding. is this miscarriage?

Not necessarily: A dull aching lower pelvic pain and lower back pain can be due to the growing uterus, muscle strain, and several other things including a UTI. If you are not bleeding, this would not even be considered a threatened miscarriage. Your PCP or OB can look into what is going on and give you ideas about how to help the discomfort. Hope this helps. Your concern shows what a great mom this baby has.