reoccurring nightmares?

I would dream quite often about being a child and knocking on my mother's bedroom door and I hear her crying. She tells me to run and hide fast. I run down the stairs to go hiding in the crawlspace in the basement. There is a small window, one foot by one foot, looking into the furnace room and it had a short string to turn on a light so see in the crawlspace. I hid under this window and back off when I hear someone pounding down the stairs. I see a large face looming in the window but he doesn't know the string is there to turn on a light. Immediantly after I wake up to see my father standing in front of me and my mother shaking her head no. The end,

It would've been impossible for my father to be standing in the crawlspace and this dream stopped after my mother died. I had this dream for 14 or more years every month or so. What did it mean?