Oo mama, totally normal yan at ako rin naka-experience lalo na sa gabi! At 28 weeks, super active na talaga ng baby especially pag gabi kaya maraming movements, plus the baby's sleep cycle pa lang yan ay developing pa lang kaya walang fixed pattern yet. Try mo lang mag-relax, basta movements are there and regular, okay ka na, pero if parang sobrang intense or may spotting, better check with OB mo just to be sure.