Pulling pain

Hi. I was diagnosed with PCOS years ago and have been trying for a baby for four years. Anywho, I use to have this pulling pain that almost felt like there was a string attached to my belly button and someone was pulling down. Almost like my inside were being pulled down and out. Very sharp and quick pain. Mostly when I bent over or moved. That was before I was pregnant. I have had that pain twice since pregnant now. Has anyone else had this? I think everything is fine because I'm still exhausted nauseous and hungry all the time lol. Does anyone know what this is?