Eh actually quite normal lah at that stage, your uterus is growing and sometimes you'll feel the hardening (Braxton Hicks contractions bah). A few of us tried timing it to see if it was regular or just random, and if it's just tightening then releasing without pain, usually fine je. But since you're also feeling the urge to pee constantly (which is normal with a growing baby), maybe best to mention it to your doc at your next checkup just to rule out anything, better safe kan, especially kalau ada any cramping or spotting along with it.