I seen a low flying dark/grey, large chevron shaped object, no lights or sound.I am constantly looking towards the sky. My boyfriend has spotted other UFO's. He said there were three sets of triangular shaped crafts that would fly together then separate into a triangular formation. That was about 3 months ago. The most recent was March 16, 2015. We were walking our dogs around 9 p.m. I was looking around at the stars, and I always notice this patch in the sky that looks like a greyish blue cluster, I am still not sure what it is, but I see it when the sky is clear. So I was looking at that then something caught my eye to the right. I felt like something was there but I didn’t see it within a couple of seconds, so I look back at that grey cluster. Then I see something again so I look more up and to the right and see a huge grey, black, chevron shaped flying object. It moved quick, but steady. It did not have any lights. I looked away and back towards it to see if I was seeing things, or my imagination running wild as usual. well I wasn't. I can't give you exact distances but It was low, close to the trees but not close enough to touch the trees. I seen it traveling for about 1 -3 minutes. I was in shock or something because it seemed like I was standing there for awhile, but it wasn’t there very long. It disappeared as it went up further into the atmosphere.I was reading about the lights of ufo's. It mentioned when the craft is in motion there is no sound and usually low, or no lights at all. I am trying to figure out why I did not see any lights, when most of the sightings of this craft have lights.After about 2 minutes I met my boyfriend on the porch. I seen these lights way up in the stars a few nights ago, but my boyfriend said it could just be stars. Well I am not sure but I was reading about the Chevron shaped craft, and found another type of craft called fireballs. What I seen was white, and moving very quickly, and shifting in various directions, unlike a plane or star. The first night I seen them, it was a full moon and the lights were flying towards the moon! My boyfriend seen it last night, there was only one, and now he thinks they were moving fast, and strange jus like I was telling him the first night I seen them. We have had other encounters, such as a bright ball of light coming from the sky, close to us.Thank you for your time, and I would really like to know more about what I saw. I am very interested in space!