Got attacked by an entity yesterday

I live in an older house in which the people who built it died in, never had anything crazy happen except doors closing, knocks, things like that up until yesterday.

It was around 1-2 in the afternoon and I was walking down the stairs and I usually stop and look back up when I get to the bottom but I didn’t and I had a thought that it may be bad luck or something but ignored it, as I reached the bottom I heard incredibly loud footsteps running down the stairs and through the hallway at me. I ran towards the door and as I get to opening it, I was pushed back by an unseen force very aggressively, knocking me to the ground, causing my chest to hurt ever since. Considering nothing like this has ever occurred I am rather concerned, I’m very careful about what I bring back into my home but it also seems unlikely that the spirit of the owners would do that, and if they did why now? And what caused the sudden aggression?