Without knowing the details of your case (or, more specifically, of the legal processes involved with it), it's hard to give an exact answer.
If the case is heading for the Crown Court (or in the early stages of the Crown Court process), it's possible that you could have several court appearances before reaching the 'P&D' (plea & directions) stage. i.e. you might not be required to enter a plea when you attend court on Monday.
Even in a summary (Magistrates' Court) case, it's still possible for the hearing to be adjourned prior to any plea being entered.
You really need to consult a solicitor urgently. If at all possible (i.e. if your work and/or family commitments allow), you should speak to your solicitor tomorrow. (If you've not already got a solicitor, it would be well worth engaging one).
If you really can't consult a solicitor before Monday, you should get to the court early and ask to speak to the duty solicitor. His/her services are limited but free. At least you'll have some guidance as to how to proceed.
Chris