Hi everyone, just wanted to share my experience over the past week to see if anyone else has experienced anything similar.
I'm 21 weeks this week, and have been having spotting on/off throughout this pregnancy, as well as some mild abdominal cramping (lower center, similar to menstrual cramps that you get right before you start your period). Not a lot of spotting, just a small amount I would notice every 2-3 weeks, usually brownish.
Last week, at 20 weeks, I had a day where I was spotting in the morning, but in the afternoon I got a bit more that was pinkish, as well as some small clots. I had also had stronger cramps that day and the two prior. I drove home from work at the end of the day, and when I stood up from my seat, it felt like I peed my pants. When I went inside, I found that I had "gushed" a large amount of pinkish/red blood, that was somewhat watered down (the blood from my last miscarriage was dark red). It was a significant amount, and after a quick change of clothes I drove myself to emerge.
Emerge did the standard bloodwork/ultrasound, and found that baby was just fine. The bleeding stopped after the "gush", and the cramping continued on and off that evening and the next day. I have had no bleeding/spotting, and barely noticeable cramps since.
I followed up with my doctor afterward, and had another follow up ultrasound today that went into more detail. My doctor suspected a small placental abruption at the edge of the placenta, but the ultrasound tech found no current bleeding, no placenta covering the cervix. The baby was completely healthy, fluid levels were fine, and there was nothing evident that would be cause for concern.
Has anyone else had this happen in a previous pregnancy, and did you find out what the cause was? Did you have any issues down the road? The experience itself was absolutely terrifying, but the doctors were all very thorough and understanding. I just wish there was an answer as to what happened/why it happened/how to prevent it from happening again.

Re: "Gush" of blood, but baby is doing fine
I am so grateful everything turned out well, and was reassured by the doctors that if you experiencing a combination of bleeding/cramping during pregnancy, it is absolutely not a mis-use of their time to have it checked out.
I haven't bled since (almost 2 wks) but still have light cramping in and off. I've been monitored weekly and it appears the hematoma is starting to heal itself.
Sometimes doctors have no clue what causes bleeding..it could be a blood vessel, placenta, SCH or something completely different.
I've been trying to stay off my feet and keep horizontal as much as possible. I've also upped my protein and Vitamin K intake to help aid it healing as well as making sure I stay super hydrated.
Just hang in there! As long as baby is ok that's all that matters!
Married 9/28/13
DS born 11/12/15
EDD 8/13/18
Baby Boy born on 1/14/13
I had something similar happen with my son. Same thing, all of a sudden I thought I peed my pants but when I went into the bathroom it was blood. They didn't exactly figure out what happened with me but suspected it was either my low-lying placenta or a minor abruption. I was kept in the hospital for a week because the bleeding started contractions and then I was on bed rest for the rest of my pregnancy. Everything ended up ok with me and my son except that he was born a little early (35 weeks).
ETA I was 23 weeks when I had the bleed. And I didn't have any more bleeding for the rest of my pregnancy.
In the weeks that followed, the spotting has completely stopped, and the cramping is mostly gone - it will come back if I am particularly active or dehydrated. Baby is progressing wonderfully, and it seems that I just had a sudden, unexplained incident of bleeding. I think that the cramping/spotting that led up to it must have been indicative of something, but the doctor doesn't seem concerned at all since everything is fine now.
So incredibly grateful to have reached 24 weeks of pregnancy, and to have put this scary incident behind me! Thank you for the kind words everyone!
Married 9/28/13
DS born 11/12/15
EDD 8/13/18
Edited bc wrong smiley