Not feeling this pregnancy

So my first pregnancy was great my husband and I were really excited. My second we were having twins and a little nervous but excited. Now I just found out im pregnant again and I kind of just feel blahh 😐 I mean don't get me wrong I'm happy. I start feeling sad, depressed and start crying out of nowhere. Then I'm okay, happy and thinking about everything I'm going to get ready to do. Then back to like no feelings. What in the world is going on?