Without more details such as where you are in the world it is impossible to say.

Where are you?

Where is the Orchid?

What sort of Stuff is the orchid potted in?

Here are some notes prepared by the American Orchid Society

Phalaenopsis Culture notes

I'm not really good with flowers at all, its standing next to the window, i live in romania(warm climate) and its potted in something like bark

Just looked up the weather for Bucharest and it is not all that warm heading into winter

The ancestors of your Phalaenopsis are from tropical climates in South East Asia.

Temperature range 20 to 30C. If you have it on the windowsill and it is 6C outside maybe it got too cold because it was close to the glass.

Needs bright light, not direct sunlight. During winter mine get sunlight filtered by a matchstick blind.

Flowers should last several months after the buds first open. Leaves going yellow are a bad sign. Usually because the mix is wet and cold.

If there is a little water catching tray under the plant make sure it doesn't have water sitting in it.

Sorry, not much help. See if you can find some complete culture notes written for Europe.