ER experience for potential contractions at 16 weeks. (Medical advice wanted!)

So I just got back from the ER and am honestly pretty annoyed. I went in on the reccomendation of my 24 hour nurse, because I have history of a miscarriage and my belly got extremely hard and I started having cramping. I assumed I was having Braxton hicks contractions early (16wks 4ds) and the nurse thought so too but wanted to make sure I wasnt dilating/ going into labor/ having a miscarriage. Well the doctor I see (an obgyn mind you) tells me its just GI issues. I explained to him I have been having normal bowel movements and no gas or other intestinal discomfort and he tells me that my uterus is still behind my pubic bone so the cramping Im feeling cant possibly be my uterus. Then proceeds to tell me that during pregnancy you have alot of aches and pains and it will just get worse the farther along I get. I didnt argue with him, just asked a few more question and went home. But the more I think about it the more annoyed I get. Im not having any GI issues. I havent eaten anything out of the ordinary. Im not sick. And Im almost 17 weeks pregnant, my uterus is not still behind my pubic bone. I can literally feel it a few inches below my belly button. The only reason I left and didnt push the matter is because my cervix wasnt dilated, the babys heart rate was fine, and I have an appointment scheduled with my obgyn monday anyways. What is your opinion on this?? What would cause your stomach to get rock hard, to have cramping and shortness of breath? Picture of me, my bump, and my husband for attention.