I recently found out that I'm 19 weeks pregnant!?

Congrats :) I'm having a baby girl too! If the doctor said the baby was fine, he's more than likely right because you're far enough along to tell. Fluttering is normal because the baby is still relatively small & has lots of room in there so you won't feel her too too much (or too consistently). For me, the movements I felt were very light & you could easily mistake them for your imagination or something. I would start taking prenatals & drinking a lot of water to keep her healthy. Also, this is the time when the baby starts getting too heavy on your vena cava if you lay on your back, so you should sleep on your sides so you don't cut off blood and oxygen to her. Don't worry too much though & enjoy the rest of your pregnancy :)