Thats a sickening feeling as you dont know if she really does miss you. On the other hand she may be a little shy in sharing her feelings just yet. Maybe give it some time. Maybe send her some flowers and see what reaction you get then. Good luck.
Maybe she feels it's too soon for you to say something like that. She doesn't say she misses you too because she doesn't yet.
your obsessing. relax shes being conversational