Alamak, this is quite rare lah, most doctors will usually remove the IUCD before pregnancy happens, so you should definitely speak to your OB/GYN soon if you haven't already, because they need to check where it is and plan the safest way forward for you. A few of us in my mum circle have had different situations during pregnancy, but IUCD during pregnancy is really something your doctor needs to monitor closely, they'll do ultrasounds to see the position and discuss whether normal delivery is possible or if you might need a c-section. Since this is your fifth baby, your body knows what to do, but the IUCD complicates things, so definitely don't delay the appointment with your specialist, okay?