cramping/backache? 3 weeks pregnant

emily • me 38 :: DH 40 :: DS 2 :: TTC #2
hi ladies!! I'm currently 11DPO and first tested positive at 9DPO. First Response is positive and CB digital is reading 1-2 weeks.  I'm nervous because I had a chemical last fall. I'm estimated to be 3w4d and have mild back pain and twingy cramps. I'm hopeful this will be a sticky bean this time since I tested positive so early; my chemical wasn't positive until 14DPO. has anyone experienced back pains and gone on to make it past the first trimester?