skinny cat

My 2 year old cat seems very skinny,she has always been small but now she seems really bony down her back, also her coat seems quite dull and dry.other than that her behaviour seems quite normal,maybe a little quieter but nothing major.Am i worrying over nothing?

has she been to the vet recently?

I would get her to the vet asap.

It sounds like she might have worms. I would take her the vet asap.
Also is it possible she may have had kittens without your knowing. I've known cats to look pretty bad after having kittens.

Just want to add: please don't use over-the-counter worm meds, they are borderline toxic and could harm your cat. Take a stool sample when you go to the vet; he/she will tell you if he has worms and dispense the right meds if necessary.
Severe weight loss is always a red flag but don't worry until you have to, could be something simple :fingerscr

Could be worms, a thyroid issue, or any number of things that should be treated sooner rather than later. I'd make an appointment with the vet soon.