Kesian you, ngilu-ngilu tu memang biasa sangat at 13 weeks, uterus you tengah stretch and adjust, jadi rasa like sharp pulling or tugging adalah normal! Tapi sebab you're a first-time mum and rasa frequent, better check with your doctor or midwife je, especially if ada bleeding or rasa really painful lah, just to be safe. A few of my mum friends had the same thing early on and doc confirmed everything was fine, so don't stress too much but do get it checked out ya!