You’ll most likely have another set of mocks - assuming you’ve just finished year 12. If you aren’t applying to oxbridge or anything medicine related then you can apply late/after your next set of mocks. If this you are planning on applying to oxbridge or for medicine then you should do some work over the summer and I can guarantee that you can move up a grade or two depending on the amount of work you’ve done. I’m in a similar situation, I didn’t get the grades needed and therefore I am not being predicted what I need. So, I’ve decided to instead do work over the summer.
Good luck!