stray pregnant cat?

hello, i have recently noticed a stray cat, whom i met back in november of 2015, who looks pregnant. I've nicknamed her Sylvis.

I really want to help her, but i dont really know how and no one else who lives with my wants inside cats because they think that i wont clean the litterbox, feed them, etc, but i already do with my dog that i have. 

Anyways, is there any way i can find out for sure if shes pregnant or not, and somehow catch her? 

thank you!

It's highly likely she's pregnant. Do you feed her? Does she let you pet her?

If so, see if she will let you bring her inside. Otherwise, you can trap her in a humane trap.

I do feed her, I actually leave out food every day and take it in during the night.

She used to come into my house and play with me, but every time i approach her she seems to not recognize me and walk away. 

I've considered a trap but they are very expensive, I actually looked into it and found out that drop traps work too.

I have made a drop trap and it works fairly well.

other than this, I don't really know how to help her.

You can rent a drop trap from your local Humane Society for a small deposit. It would be the best way to trap her. It's great that you are feeding her.