Sayang, ini boleh jadi Braxton Hicks contractions (fake contractions) yang common masa trimester ketiga, tapi sebab you're only at week 6, please call your doctor or go to the clinic asap , better safe than sorry, especially first pregnancy! Perut yang tegang dan keras tiba-tiba memang boleh jadi normal stretching, but on the safe side kena check with your gynae to make sure everything's okay. A few of us mums kena pergi even for small things masa early pregnancy, and honestly it gave us peace of mind. Don't worry yourself alone, reach out to your doctor today, okay? They'll check and put your mind at ease!