Hey mama, back and lower back pain is pretty common sa pregnancy kasi lumalaki ang baby at nagbabago ang posture mo, pero since you're not in severe pain yet, it's still good to check with your OB para ma-rule out kung anong causing it talaga, could be normal pregnancy stuff or something they should monitor, pero better safe than sorry! In the meantime, try to rest more, use proper pillows for support, at avoid heavy lifting kung kaya mo. Sending you comfort, mama!