True labor symptoms for a week?

Every article I've read tells me all the signs of false and true labor and I have been having true labor symptoms for a week I'm about to be 38 weeks in a couple days and I've been getting checked weekly and my cervix isn't changing just had it checked by my doctor. My symptoms are bad lower back pain very tight contractions that start from my sides then go to my front?? I get them every 2-5 minutes, my uterus feels so heavy can barely walk from being so heavy And very sharp menstrual like cramps also feels like I'm being pinched in my cervix and also I've been having very loose bowel movements and I've never had that before but it's been like this for a week already and no change to cervix still closed I'm so confused??