Thanks everyone! I had cats growing up, and even though my husband is allergic and we can't have any pets now, I kind of like having an outdoor cat. She was just starting to get to trust me (she would come onto the porch even if I was there, and would sniff at my hand, although she backed away...
I (perhaps stupidly) starting feeding a stray that was hanging around our porch. She is now pregnant and I'm guessing going to deliver soon. When she went into heat the first time (which was a completely new experience to me) I immediately contacted local TNR places, since I didn't even know...