It almost collided with the Coast Gaurd Helicopter

I was standing on my front porch and heard a helicopter coming. So I looked and it was the Coast Guard heading right towards my house from the Northeast heading southwest. All of the sudden there was this white cigar shaped thing (with what looked like a long window in the middle of it) coming straight towards the helicopter from the southeast going to the northwest.
I thought for sure it was going to collide with the Coast Guard. Thankfully, they were much faster than the white cigar shaped thing. The cigar was going so slow that I could not hear the helicopter any longer. I saw it long enough to open the door holler for my daughter to come here close the door turn back around and still see it before it went behind my tree.
The sky was blue no clouds at all, no birds. I could see it through my apple tree branches. It was quite thin compared to the helicopter. The I could see what I can only sense was a window right in the middle, shaped like a cigar. I could see the white all the way around the window. It had no wings, no tail, no sound at all. It was one single object. It was much slower than the helicopter. It had no lights.
I thought if it was an aircraft it would have been illegal for them to fly so closely. It was also very low to the ground.