Congrats on the twins, mama! Yes, normal yan sa early pregnancy especially with twins kasi mas maraming hormones at stretching na nangyayari, a few of us preggy twins moms naman nag-complain ng same cramping at lower back pain, parang period cramps talaga, so hindi ka nag-iisa don. The LBM and skin allergy ay maaaring related din sa hormonal changes, pero since you're still in the early weeks at may ganitong symptoms, mas okay na i-mention mo lahat sa OB mo sa next visit para ma-monitor properly, lalo na with twins kasi special care sila need. Wishing you a smooth pregnancy ahead!