Is it bad to have my first time sex if my bf having experience but I am a virigin

Hi Mitan. I have read your post and in having trouble trying to work out what your actually asking. You say your bf has had experiences I take I you mean he has had sex with the other girls and when you say he has a large one I'm guessing you mean a big penis? I'm not sure what you mean by this bit though.....My friend to me that normally we will hope that he can finish soon during the first time due to we are in pain or uncomfortable, the pain will be greater if he is big? When you say It will be worse if he is having experience and will last really long. Do you mean will it be more painfully if intercourse lasts a long time? You say you have prepared lubricant what sort of lubricant? An last of all have you thought about using any form of birth control like a condom?

I mean he is big in his organ and also if I am in pain but he lasting very long and means I will continue hurt until he finish. I have prepared KY and also I am on pill.

First of all don't let your bf pressure you into anything you don't feel ready for. Not every girl will feel pain all the time specially if your relaxed and normally when you get into into it the pleasure takes over.
No amount of extra lubricant will make it easier and you should produce enough lubricant yourself if there is enough foreplay and that will also help relax and expand your vagina resulting in less pain.