Sayang, anything yang membuat you worried during pregnancy kena check dengan doctor, jangan tunda, okay? Go see your OB-GYN soon, especially since you're already concerned. At 18 weeks, some hardening is normal (that's your uterus growing), but the combination of that plus feeling baby gerak jarang, your doctor needs to check properly and make sure everything's fine. A few of my mum friends went through similar worries and their doctors did a quick scan to put their mind at ease, so it's really worth going in. Don't stress yourself out, just book that appointment and let the expert check you out. Better safe than sorry, mama!