Question: if your water broke while you were on the toilet how did you know?

I'm FTM and 40+5. Finally dilated to a 1 and got scraped at our appointment yesterday. I have been having really bad back pain and cramps all night since then and all the sudden this morning after using the bathroom all my pain has stopped. I feel like there was a lot of liquid but I couldn't tell exactly where it was coming from. I tested positive for strep b so my Dr. said as soon as my water breaks I need to go in to start antibiotics. I'm kinda freaking out at the moment.