Uterine Hardening

Hi mommies! 13 weeks preggy here and my OB said I have a Uterine hardening. She gave me meds but if hindi ko na daw feel na matigas then no need na daw magtake. Medyo nalilito lang ako kasi ayuko naman magtake if hindi naman needed. Sino po dito nakaranas ng Uterine hardening and what do you do? Thank you.