Hi mama! Some cramping and backache in early pregnancy is pretty normal kasi lumalaki na ang uterus mo and hormones are all over the place, pero since you're worried and especially after your transvaginal ultrasound, I'd really suggest checking in with your OB just to be sure everything's okay, better safe than sorry talaga, especially pag first pregnancy or if the pain gets worse. A few of us mums had similar cramping around that time and it turned out fine, pero your doctor should really be the one to assess you properly.