Bleeding at 16 wks (tmi/possible mc?)

I apologize in advance for this being long. I have been keeping this in and trying to not take up board space because i feel like i am failing at being pregnant. I am 16 wks today with a naturally conceived twin pregnancy and have had a couple bleeding episodes. The first was on 7/17 and lasted 4 days. My OB advised me to go to the ER where the ultrasound and bloodwork revealed unknown vaginal bleeding. The second episode started on 7/26 and has not stopped since. The last 9 days of bleeding have been so challenging physically and emotionally. I have seen my OB several times, the endocrinologist and the perinatal doctor and still have no conclusive answers as to why this is happening. The placentas are placed and attached properly, the cervix is closed, and latest ultrasound reveal 2 active babies with heartbeats of 128 and 143. All the doctors tell me that some women with multiple pregnancies experience bleeding throughout their pregnancies. I was told that bedrest would not really help because it will not change the outcome of a miscarriage. All the genetic bloodwork testing has come back normal. However, nothing about this feels reassuring, it feels horribly wrong. I keep going into every ultrasound clenching my teeth because I fear seeing the screen without that flash of a beating heart. Besides the bleeding which is heavier than most of my regular periods, I have these horrible cramps that wrap around from my back to my lower abdomen right before the worst bleeding. Battling the world of infertility the last six years was a nightmare, but I clearly remember feeling relief when i finally had the DOR diagnosis. It made me feel like I was not crazy or imagining all the problems with getting pregnant. It made me feel like I could learn about the condition and make a plan of action. Hearing now from every medical professional that there is nothing they can do before 20 weeks is slowly eating away at my hope. I know that life includes loss and I am constantly praying for His will to be done and the peace in my heart to accept it. It feels like my heart is breaking with every blood drop and cramp. I am not certain if anyone has had a similar experience or suggestions for determining what is wrong, I am open ears. Again, sorry for the length, babbling and emotion, I just wanted to hear some answers from women who I know have experienced so much.