25 weeks and currently in the hospital

I went the bathroom because I needed to pee. The blood looked like a full blown period. I had clots and all. I had to drive myself to the ER and it was literally the longest 10 minutes of my life. I’m 25 weeks and one day. Baby is on the monitor and a high heartbeat. Can someone explain why I may have had this bleeding? I’m not feeling contractions just some pressure. Any stories, good or bad. I just wanna know what’s going on 😭 I don’t understand why I would be bleeding at this point. I’m waiting for an ultrasound