Sorry, I may be feeling a bit grumpy this morning, but this post is genuinely meant to be helpful for other buyers, if not for this one. 
Yeah that's why you should have been given hip scores. V unusual for labs to be sold without?
Welll no, not at all - there are upwards of 30,000 Labradors registered each year, far more than that again sold unregistered, and there have been approx. 15,000 hip scored in total over the last 15 years - so, far more unusual for them to be sold with both parents hip scored ... but, the tools are there and puppy buyers should follow them for their own peace of mind.
Mind you, hip dysplasia is both inherited and environmental, so even a pup from two parents with good hip scores can very easily be ruined by poor nutrition and incorrect exercise. It's a difficult beast, and anyone buying any puppy from a breed prone to it is should reduce their risk by buying from a litter with parents with good scores, bred by a breeder who consistently produces good scores, and then follow their instructions for rearing to the letter.
(Obviously it goes without saying that any crossbreed of two breeds prone to HD is equally likely to be an issue, but you are far less likely to be able to find the kind of breeder described above.)
Anyway, OP - your puppy is very very young. If the vet echos your fears on Monday, then to be honest I would go back to the breeder and make this their problem I'm afraid. It is only by doing this that we will ever make breeders more responsible.
To keep this puppy IF she is displaying signs of HD (and none of us here can tell from your description) would be signing you up to a bucketload of heartache and expense, and I would hazard a guess that your insurance would not cover you.