Aah, sakit perut, pinggang dan pinggul tu memang common masa pregnant 23 minggu, ligament stretching, baby's weight, dan postur yang berubah semua contribute. But since it feels exactly like period pain, I'd really suggest check with your doctor or midwife cepat-cepat je, sebab at this stage ada few things they want to rule out, especially kalau sakit tu constant atau getting worse lah.