At 35 weeks at 6 days, it's totally normal para mababa ang tyan, yan talaga ang nangyayari as baby drops and prepares for delivery, lalo na kung first baby mo kasi mas maaga. One of my mum friends said ang kanyang tyan bumaba ng sobra two weeks before she gave birth, tapos parang nawala ang shortness of breath niya, pero mas mabigat ang pressure sa pelvic area, so definitely not the same experience for lahat! Best to mention it sa OB mo sa next checkup para ma-confirm kung talagang engaged na ang baby or if there's anything else going on, kasi bawat pregnancy ay unique talaga.