Aww mommy, back pain sa pregnancy is super common talaga, especially pag second baby na kasi ang katawan mo familiar na sa stretching, pero since you're still in first trimester, best pa rin na i-mention mo sa OB mo during your next visit para ma-rule out kung may ibang cause or kung need mo ng support like a maternity belt. A few of us moms swear na tumutulong ang proper posture at light stretching, pero definitely check with your doctor para sure, lalo na pag increasing na ang pain o may ibang symptoms. Hang in there, mommy!