Big Scare on my Birthday

Spring
My birthday was Wednesday, on Wednesday I went to the bathroom and noticed some blood. I am about 8 weeks pregnant with twins, one is very small and has a slow heartbeat. I immediately called my fertility clinic and she said I could either go to their clinic in Mobile since the close one I usually go to was closed or go to urgent care. So my husband drove me to the Navy hospitals urgent care. They did a pelvic exam and said everything looked fine. They tested my blood and urin which were also fine. They did an ultrasound and told me that they could only find one baby but he was fine. I have O negative blood so I had to get a shot since my husband is O positive. I spent my birthday and yesterday despressed that I had lost one of my babies. 
My fertility clinic had me come in for an ultrasound today and she was able to find the second baby but he is still small with a low heart rate. But I fear he needs a miracle or he's not gonna make it.