Hi mama, okay lang yan at common sa maraming preggy moms, ang Braxton Hicks contractions na yan usually start around 16-20 weeks, lalo na kung second pregnancy mo na, kaya hindi ka mag-alala! Since your doctor already gave you Gestron and the tightening is lighter na and shorter, that's a good sign na tumutulong ang gamot, pero I'd still suggest follow-up with your doc sa next check-up para ma-confirm talaga na normal lang and walang underlying concerns, especially if it happens pa rin frequently or becomes painful.