I need some advice

Renee • 33 yr old FTM with soon to be 10 yr old daughter. Have a 13 yr old "bonus" daughter and our 🌈 daughters, A'Siah & A'Riah, EDD 10/10/17
So Monday I had some bleeding occur (bright red) which later turned to a brownish color. After a ER visit and 2 ultrasounds, my twins are doing great 👏🏾👏🏾 I'm currently 8w2d and babies were measuring 8w4d and 8w2d. My only concern now is I keep passing tissue. I know deep down in my soul my babies are just fine.....I just want to know if anyone else experienced this and if so, how long did it last? Thanks in advance for your support