I'll reply to your PM separately about the holiday and focus on the pregnancy issue here.
My strong advice to you is to try and put the holiday out of your mind and focus on all the other issues. £1000 to cancel is a lot of money but it is a drop in the ocean in the grand scheme of things in terms of your life together.
You can terminate your pregnancy if you don't want to have a baby just yet, that's absolutely fine. But don't do it just because of a holiday. Because if you don't really want to terminate or you regret your decision, you will not enjoy the holiday anyway. You'll be in some amazing place thinking about the newborn baby you could have been holding and it will just make you feel sad.
So focus on other things.
You say you see yourself being with your partner in the long term and that's great. Do you want to get married? If so, do you want to be married before having kids? (If you do, this can be done in a short time frame and for not much money.)
You talk about 9 months' maternity leave which suggests you would be planning to go back to work afterwards rather than be a SAHM. This would put you in a stronger financial position, even if being the working mother of a young child is hard.
If you do have a baby together, you should try and get it into your head that there is no more your money and his money. You are no longer boyfriend and girlfriend, but a family with a child. His wages plus your maternity pay would just be your joint household income. Please don't fall into the trap of thinking that it would be your responsibility to fund your own maternity leave and your responsibility to pay for childcare. These are joint responsibilities. And your partner should also be doing his fair share of housework and childcare duties. If he is in a position to take paternity leave or even shared parental leave, that would be absolutely wonderful for your relationship as equal parents and for his relationship with your child. If you can see it working out like this if you have the baby, I would consider continuing with the pregnancy.
If, on the other hand, you have any niggling doubts about your partner, or how you will share financial, household and childcare responsibilities, or even just whether you want to have a baby at this time in your life, consider the alternative. There is no shame in having a termination if you just aren't ready to have a baby.
Only you can decide.
But don't let the holiday be the deciding factor because even the threat of a £1000 cancellation fee really is trivial in the grand scheme of things.