How do I pierce my own belly button?

Hello. To start off, I'm 14 years old and I want my belly button pierced really badly. I used to be over 160 pounds, and I dieted to the point that I'm now at a healthy weight for my age and height, - about 125 pounds. My motivation was that I would; A: be able to wear a bikini for the first time in my life and B: be able to get my belly button pierced. Let me get this straight right now, I am NOT some little trashy whore that wants to run around with my tummy hanging out all of the time. I merely got sick of being the ONLY teenage girl on the beach in a tankini covering my whole stomach. And I don't know why, but I've always thought that belly rings were the cutest little things. My mom knew that my goal in losing that weight was obviously to be healthier, but I really wanted to have a reasonable body, and be able to go out on the beach in a bikini. She never gave me a straight yes or no answer, but I really just assumed that since she isn't conservative or anything, she just wouldn't mind. Around my birthday (December), my mom's best friend offered to take me to get it done where she had, and one of her friends works there. My dad was fine with it and told her to just take me, even if my mom said no. My mom's friend wouldn't do that to her best friend, so she talked to my mom more and more about it and she eventually (according to my dad) said that she'd let her take me to get it done. I backed out last minute because I was too self conscious at the time to show my stomach anyways. Now, I've toned my stomach up more and my mom has taken me out to buy like three different bikinis. Being conservative or whatever is NOT the issue with her. I recently brought the idea across my mom again that I'd love to get my belly button done before our vacation to Florida this August. She shot it right down and screamed at me about it. I have no idea why. Earlier this year, she didn't even want me to get second holes in my ear. She refused to let me. I, being the rebel child that I am (when I have to be..), sterilized a needle and some old earrings and did it myself. She ended up thinking it was cute and I wasn't punished at all. In fact, I walked in and showed her right after it was done and her only complaint was, "You better hope your ears don't get infected.". They turned out fine, because I kept them clean at all times. I'm ready to do the same thing with my belly button. I don't really care what she has to say about it, it's my body and I can do whatever I want with it. I worked this hard to lose all that weight and look presentable, now I want to feel even more proud of my tummy when I'm at pool parties with friends and on vacation this summer. How do I go about this? I can get a belly ring to put in at my local mall when I go shopping with my friend, or even ask my dad to order me one online. I have needles here that I can use. I warned her that I WILL do it myself and that she knows it, and she threatened to punish me. I'm willing to take whatever she gives me, but she can't force me to take it out and keep it out. She'll end up getting used to it, I know my mother. Please don't try to stop me, once again, rebellious child when it comes to things with my body like that. (I'm not a bad kid though, never done drugs, never smoked, never drank, don't plan to) I only have this attitude when it comes to piercings. (: Please no angry mom answers either. I just want people who have experience to tell me what to do and how to do it! Thank you!