Help! Flowers on my Orchid (Phal) are falling

[Sonia1215]

Hi everyone. I have had my flower for a month now i believe. I water it ones a week it's planted in moss. Like you will see in the picture i have it on my kitchen window. It's that dark because its night right now.
One of the flowers just fell off right now i checked and the plant it's no dry. I am aware that it is part of the process for the flowers to dry and fall but it can also be that it is dying.
Since this is my first orchid i have no idea how it would look like if it were dying. My husband gave me this flower and i really wanna keep it alive. I wanna prove to him that i can do it. So just making sure that everything is okay