Fluid around baby B's heart 😰

Had my first ultrasound done yesterday at 8 weeks 4 days. My husband and I were so excited when they told us we were having twins. Doctor came in 30 min later and told us she was worried about baby B. Baby B has fluid around the heart and the doctor said she wanted us to come back in 2 weeks to see if the fluid went away or if baby B passed. So many different emotions are going on. Anyone else gone through something like this? This is our first pregnancy.