Alah, week 5 tu memang normal je kalau rasa sakit atau kram-kram ringan, especially kalau first time pregnant! A few of my mum friends cerita yang sama, ada yang rasa pulling sensation atau mild cramping tu part of the whole implantation dan uterus stretching process. Tapi kalau sakit dia macam really intense, bleeding, atau tak hilang-hilang, definitely go see your doc la, better safe than sorry kan, especially at this early stage. Congratulations on your pregnancy, by the way!