As your USG report reveals gestational sac
, then you are definitely pregnant. Lower back pain is quite common during pregnancy
period due to increase level of relaxin hormone. Mild abdominal cramp
may occur with uterine contraction. All these things are normal phenomena and nothing to worry.
Take folic acid
supplements, protein rich diet, avoid long journey/heavy work, maintain personal hygiene, take adequate rest and do repeat scan in later months for detailed feto-placental profile. Do periodic check up and complete suggestive investigations.
For direct consultation with me, you may visit my profile on http://www.healthcaremagic.com/doctors/dr-soumen-patra/63326.
Be well & take care.