what kind of worm is this?

hi folks

My chickens have been having a lot of health issues lately, and to make a long story short, I've been thinking it might be worms.

My vet did a fecal sample twice and said there weren't any worms, even though I can see little segments that look like the tapeworm pictures on this forum. (like rice).

Also, yesterday I saw a LONG segment which almost looked like a full tapeworm. The pieces are flat and look like fetuccini, except they are fairly narrow in width. The long piece of worm I found does not look like it has segments. just like fettuccini, except with the tail end starting to get into smaller segments.

Any ideas what this might be? is it possible to get a negative on the fecal sample and still be seeing all these worms?

Please help. My girls have been really suffering.