You might want to open up the subject of circumcision to your parents. The subject may be a little uncomfortable... here is a tip:
For example you may mention that you've read some articles that talk about the advantages of circumcision, and that you've started to wonder about what you should do. Then you may ask your parents about what they think of the benefits of circumcision. If they seem to be favoring cicumcision in terms of health benefits, then say that you will try to read more on this issue and then decide. And thank them for their opinions. Later, after you think more about circumcision, you can go and tell your parents that you do want to be circumcised.
There is absolutely nothing to be ashamed of this process. Do not feel frustrated. Your parents will be happy when you open up a subject like this, and show that you are thinking and doing a research about something that is very important for your health.
It is totally up to you whether to get circumcised or not. You are very lucky that you have parents that are asking your decision about whether to get circumcised or not.