My cat was defo pregnant but wasn't a houde cat,just came in 2 get fed and roamed about my back garden, however 2 days ago I notices faint blood marks on her hind legs, her belly has went down now but her nipples are huge! I can't find the kittens no were and don't no what to do?? Could it be she's ready 2 have them because she's in the house mor than often this past few days? Please I need advice

It sounds like she has had her kittens. I have no idea where they are. Watch her to see where she goes.