Three triangle shaped aircraft flying at low altitude silently.

I was exiting my vehicle and pulling my child from the car seat while in my driveway. I saw three red lights and a strobe traveling from the north and heading to the south. I decided to stand and wait while holding my sleeping child to see the aircraft.
Eventually I could make out that there were 3 aircraft. Two in front and one in the rear. One of the aircraft flew directly over me. I could tell that the two lead aircraft were isosceles triangle shaped with underside red lights at their centers. The rear aircraft was an obtuse triangle shape with a red light at the center, but with a strobe on its nose. None of the aircraft had any navigation lights (no red and green wingtip lights, or tail light.) There was the one strobe light. These aircraft flew silently, very slowly and seemed to be at a low altitude. They appeared very large. I could not make out a color. These aircraft were not trying to hide from any observers on the ground. While it was dark and the aircraft were silent, anyone could have seen these things.
I use to fly UAS while in the military and have worked on flight lines. I am NO expert. I have a very limited experience, but I do have some experience. I do not believe these aircraft to be extraterrestrial.