Hi I Just Had A Natural Miscarriage 2 Days Ago

Hi I just had a natural miscarriage 2 days ago and my Dr said that from the ultrasound pictures that most everything was gone from my uterus. They gave me Tylenol with codeine for pain but it hasn't really helped and all last night and today I have been having severe sharp pains in my lower abdomen, pelvic area, back and in my rectum. I feel like my intestines are full of gas and it hurts to sit and walk and even lay down. I feel like I have to pass gas but I cant! And when I have a little come out it hurts so bad. It's like someone is constantly stabbing me in the rectal area. Please help me it makes me nervous and I can't take the pain.