Please help! Insects around bedroom, what are they?

So last night I was in bed and I noticed a tiny insect crossing my laptop screen, I killed it and thought nothing of it. Then another crossed a while later. Then I notice one or two walking across my bed sheets. Now, initially I thought they were bed bugs, but they don't really look like bed bugs. These bugs are tiny, like a speck of dust and are a dark grey/black with a lighter spot on the centre of the body. I have also had itchy hive like bites on my body, but these possibly could be hives. So today I hoovered my whole room, all around my bed, my mattress etc. Then I washed all my bed sheets and my curtains, as there was a good few on them. Later on I then noticed a number of the bugs around my window and window sill. Does anyone have any idea what these bugs might be? Thank you!