Another stray dog came to my house and IDK if she's pregnant?

PLEASE READ thoroughly because alot of people write without thinking or rereading! ANYWHOOO I get strays ALL THE TIME and it is very sad and of course i take them in bathe them, feed them, and give them water and I open them up and give them the opportunity to trust humans. I have a stray cat and a stray dog that I kept for 6 months now and 2 strays that I gave to the rescue and I have 2 of my own dogs on top of that =/ well....another stray came here again but was sooo terrified of anything and everything and I can't tell if she's been neglected or abused or probably both. She's acting weird so IDK if it's cuz she's never had normal interaction with other dogs or people but my dogs have opened her up a lil bit and she has not left my side and even freaks out when I go to the bathroom...i have to hand feed her to eat and it's so hard and IDK if I want to keep her but in her condition, I can't seem to call SPCA. They would either put her to sleep or IDK because she's so weird and doesn't move and she trust me but not fully yet and I've had her for 6 days already...IDK if she's pregnant as well, how can you tell? her nipples are big and hard but loose and I can't tell if it is from a previous litter or if she's in the beginning of her pregnancy PLEASE HELP..i am experienced with dogs and especially abused and neglected but she's a little different and because she acts weird I think she's pregnant...She poops 4 times or more every day since I had her and she eats and drinks more than my dogs and she's smaller than them as well and her rib cage is big and hard but her stomach is mushy and nipples seem loose like hanging kind of...she goes potty outside but waits till I sleep to crap somemore in the house and it seems she can't help herself or hold it so she releases at night..she DOES NOT do that at all during the day and she chews weird things that I never seen dogs chew and she started shredding a blanket I gave her in the middle of the night. She's more awake and alert at night if anything...I was going to keep her and take her to the vet but I have alot of dogs as is and idk what to do with her...she is also blind in one eye so idk if someone did that to her because she seems like she's not used to seeing out of one eye and cautious with her steps and accidentally bangs her face or runs into things on the blind side...she seems healthy overall though