Is it possible I only have one ovary? Help!

Okay so I'll try to make this short...when I had my US at 8 weeks, they couldn't find my left ovary. I was more concerned with baby, so I didn't care. Today, I am 11w 5d and it was an abdominal US...and she really dug in there, still couldn't find it.

She didn't seem worried and I asked if I should be, and she said no, it could just be hidden, and even if by chance I didn't have two, one was obviously working.

Has this happened to anyone else? I'm super constipated and she said the left ovary is often behind the intestines. I have always had normal periods and have never been diagnosed with any type of issues, and had US done when I was in college to check for cysts, and I'm PRETTY SURE they checked both to rule it out- nobody has ever told me that I might be missing an ovary!! I also got pregnant shortly after we started TTC (not that that means anything but I just didn't even think this was possible!)