Weird noises. help?

So I gave birth a week ago and the other morning when I was falling asleep it sounded like someone was washing their car. Happened twice. Then I heard a sharp whistling like someone was looking for a dog. I know these were in my head. Mentioned it to my doctor when I took baby to appt. he said he would only be concerned if I heard voices. Tonight I'm in the nursery falling asleep in the armchair and I hear a siren type whistling (but not quite as harsh) and seems like there is flashing lights. Tried to call out to my mother in law in the next room. Couldn't talk/wake up. Also tried to raise my arm to knock something off the shelf to get attention. Couldn't move unt l it passed. Any thoughts? It was a bit scary and doctor didn't seem to care. I think he maybe thought I was dreaming?