Ohhh sayang, tu likely BH (Braxton Hicks) lah! A few of us tried timing whether it comes and goes, and kalau tu memang ada pattern atau rasa mcm tightening then relax, tu normal contraction practice je. But honestly if rasa vibrate mcm flutter or spasm type, best check with your doctor or midwife sebab could be anything from baby hiccups to electric-type sensations yang kadang boleh happen, better safe je untuk confirm everything's okay with baby!