Unexpected visit to the ER

On Sep 1, I went to bed at 10 pm and made a mistake of drinking about 2 glasses of water as I was thirsty. At around 2 am, I woke up with the urgent need to pee but nothing came out. I tried squatting in the tub and different positions and nothing. The pain became excruciating when I walk so I went to the emergency and they put a catheter to drain the urine. Boy that was a big relief! The OB at the hospital didn't think it's related to pregnancy as I'm only 10 weeks and the urine tested normal so no infection. She doesn't really know why it happened so I'm being referred to a urologist. But I've googled and noticed that it's common for women with tilted uterus which I have.  I'm hoping this is just a one time event and I think I will avoid drinking water 2 hours before going to bed.  So far my peeing seems to be back to normal, still more frequent but at least a steady stream first thing in the morning. So maybe I've just held it too long.