Cat acting weird.

So I have a pure black polydactal cat named Sushi who is just under a year old roughly. Now I rent the second floor of a house that has a huge flat roof just outside my computer room window that is probably the same size as the backyard, anyways she was always pawing at the window and eventually tore the screen so she could get out. So after seeing that she can't get down from the roof and wouldn't jump I decided to let her go out there when ever she wants and she loves it out there, and goes up to the 3rd floor roof to sun on the upstairs neighbors deck, even goes out when it is raining hard and has been for several months. My neighbor upstairs loves her and I know for a fact would never hurt her or anything.

I spend a lot of time on my computer because that is where I do most of my work so I am normally there to greet her when she comes in from outside seeing as how the window is right next to my desk. So tonight she was out for a while it was raining pretty hard but not a big deal because she loves the rain. Anyways she pops her head in the window and I greet her but she is looking around my computer room at everything acting all scared. I called for her and reached out and she backed away from me which she has never done before and has no reason to as I have never hit her or even yelled at her for that matter. This goes on for a while her slowly inching her way in and than suddenly backing off for some reason the whole time acting totally freaked out. Finally she comes in I reach for her and she jumped and tried to get back out but I wouldn't let her. She has this huge cat tree scratching post thing in my computer room which she loves and freaked out when i put her in it. I held her for a bit, she ate some food and eventually mellowed out, but I am wondering what could possibly freak her out so bad. I was starting to think my apt was haunted or something and started freaking myself out lol. I live alone so I know no one tormented her and as I said earlier my neighbor upstairs seriously loves her I know for a fact would not hurt her and would never give her anything or feed her anything without my permission. So what got into her? Or is it just another female thing I don't understand?

She could have seen or encountered something on the roof that scared her. I doubt it's you. I would keep her inside until she's acting normally again. Are there any big raptor birds in your area?

I agree--something, someone probably spooked her--maybe even a smell.  Remember, cats can smell a LOT better than humans can.  I'd give her lots of attention if she wants it, alone time if that is what she wants, and let her tell you when she wants to go out again.

I assume she is spayed.

Nah I live in the city so, no raptor birds. Yes she is spayed, She's fine now just had me a little spooked she has always been a bit skittish but never with me so it freaked me out a bit. All is well now I just got worried seeing as how she is my furry little buddy.....and blatant bed hog lol.