My girl is 7 weeks pregnant and has started to bag up for want of a better description her teats are quite big and full of milk is this normal I dont remember it happening quite so soon last time .... or am I worrying for nothing.

They vary so much.  I've had girls like yours, and I've had girls that had no milk until after whelping.

Yes one of ours gets it right at the last minute, but another had it from about 6 weeks last time she had a litter, but she was fine, still went right to her due date

my girl is only 5 weeks pregnant and her nipples are leaking too, only slight though.