3 lights seen in a triangular shape, Cabo Rojo, Puerto Rico

One night, at midnight, as I was saying "good night" to my boyfriend, I was on my house's balcony where I saw some lights, the same color as the stars but what caught my attention was that they wouldn't move. Those "lights" were far from us, above a dark hill next to my neighborhood not that high in the sky, exactly aligned to the front of my eyesight. I was puzzled and I asked my BF who was facing me to take a look and I asked him what it was. He took a quick look and told me those were helicopters. I quickly answered back: "unless there are two helicopters next to each other just standing there...." and then I noticed it couldn't be because there were 3 lights forming an obtuse triangle and helicopters just don't stop in the sky NEXT TO EACH OTHER.
I wanted to believe my BF, so I said goodbye, came inside the house, closed all the windows (that my parents would always keep open) and went to bed shaking. I calmed myself down and fell asleep.
 Next morning I called my best friend as I usually would do every morning and the first thing she says is: "do you remember last night when you dropped me home and we saw the guy's cars outside but the guys were not there?" Since my best friend was a quiet, smart girl the way she was trying to tell me something was wrong made me feel as scared as the night before. I asked her what happened. She said that when she went inside her house the guys (her brother and his friends) were inside, scared, and told her that minutes before they were out in the street as usual when they saw a round light standing there in the sky and then they saw smaller lights coming into the bigger light and then separating away. They went up to the roof of the house saw the lights for a couple of minutes and then the lights flew away.
Then I believed what I saw was a UFO but I tried to supress the memory of it until now.
FYI, I lived in the rural part of town, SouthWest of "downtown" Cabo Rojo and my friend lived East of the center of downtown Cabo Rojo, which is a 5 minute drive away. All of the witnesses were older than 20 years old and College students.
Witness indicates that date of incident is approximate.  PD