I arrived the day before surgery and had only lost 2 of the 10 lbs I was supposed to lose. No problems, they still did the surgery. I am going on 4 weeks post of now and have not had any problems with heartburn. Everyone is different of course. It is normal to have second thoughts, I'm 4 weeks post op and still worry that I'm not going to lose the weight. Make a list of pros and cons if it helps.
You have to make the best decision for you, at the end of the day you are the only person that has to be okay with your choice.
Best of luck!