parsley - you worry too much. I certainly wouldnt put anything on your profile about your size, why should you. stick in in the body type bit and leave it as that else it will look like you have an issue with it.
Im speaking as somone who goes up and down by 2 stone every 6 months. ( ridiclous, but there it is) Currently im in a fat phase :)
Last week the puppy was telling me how stunning/ perfect/ beautiiful/ etc i am and how he cant believe hes lucky enough to be with me ( haha, not now hes not!)
and friday night the pirate, said ( thoughout the course of the night) that i was like some kind of sulty nigella lawson, that i was capitvating, charasmatic, like some kind of seductive, raven haired beauty. that i was dainty and petite ( !! hahahaha!!)
I am a size 16 at the momment.
( i have an unfortunate medical condition that makes it very hard to lose any weight at all, following a docs appt in may where i was told to give myself abreak, i would never be thin, i had to accept myself for what i am... i have :) )
It matters not what your size is, but is all about confidence. If you are appolgetic for your size, or self conscience thinking you are trying to measure up to some ideal and failing, then thats not good, nor attractive to men. And look around you, are all the people in relationships, tall, thin and beautiful, NO. they are not.
Stick a picture up, look happy, be yourself and they will love you!
you need to change your thinking with online dating, else quite quickly you might feel crushed, its not really for the faint hearted and has a high rejection rate. But start looking at it from the angle that these men need to impress you, not you needing to impress them ( by looking a certain way)
with the sites, it very much depends on the area you live in. Join a few of the free ones, you have nothing to lose and can always delete your profile if you want. and dont be worried about who might see you on there, as others have said, if they have seen you on there, its because they are on there too :)