31 weeks and 4 days blood clot loss (TMI)

So I'm back in hospital AGAIN!! I was only discharge yesterday after bleeding but it stopped and went down and then went away and I had a great nights sleep and I woke up feeling better than ever, had breakfast drank loads of water felt fine until a round 6.45pm I was having a nap with my partner and around 7.30pm I felt a slight gush thinking it was just a little discharge I looked down at my pad that was covered in red blood, I was like ' god sake not again' and then I heard a plop and it was a big clot about size of a table spoon.. at this point I was a bit worried as the first time I bled I had nothing just bleeding... so I have come into the labour unit as they told me too, they checked me over and said that it defo came from the womb and it's defo not the placenta but they are unsure what's causing it.. so I have to stay in again. Baby is fine heart rate was fine, she had dips but she then had a steady heart rate..

Anyone ever had a bleed like the second time and the lost a huge blood clot and then had to have a c seaction or went into labour? Because they said they are concerned due to it being the second time and it was only the other day I lost blood.

They said if it happens over night then they will have to inject me etc... any advice

***WARNING PICTURE IS BERY GRAPHIC***