Do a blood test
for beta hcg to confirm/exclude pregnancy
If test is negative again,then do a USG lower abdomen to rule out underlying pathology if any.
Stress,emotional upset,over wt/loss,irregular eating habit may cause indigestion
and hormonal imbalance leads to above features.
Consult with your doctor and take advice/medication according to your need.
Take healthy diet,avoid stress by doing deep breathing/yoga and need adequate sleep. You may use muscle relaxant
gel for LBP.