Wah, you're so close now! Honestly, the tummy pain and hardening could be Braxton Hicks or early labour signs, at 38 weeks anything can happen lah, so I think best you call your doctor or midwife just to be safe and let them check you out, especially if the pain is getting stronger or more regular. A few of us mummies experienced similar things before our due dates, some were false alarms, some weren't, so better get professional advice to know for sure!