Is it wrong for me to be upset?

Growing up being the oldest child has sucked. Every year I would ask for something my mom would say no but when my sister turned that age it was okay for her to have it or my mom gave her what I wanted it too. 
For example. 
Age 14 I asked for an iPod touch. My mom got me one for Christmas but also got my sister one (age 12). When I was 12 I had asked for one but the answer was no you're too young. So what's the justification for giving my sister one when she's 12? 
When I was 15, one month before turning 16 I asked to get my belly button pierced and my mom said "no that's for sluts". So I waited till I was 16 when I could legally get it done on my own. 4 months before my sister turned 16 she asked my mom and my mom took her to get it done. Again, my sister got what she wanted. 
When I got my first phone I asked for a blackberry and my mom said no because the bill would be $10 more a month and I thought that was understandable and offered to pay the $10 out of my allowance. Still the answer was no. So I got a shitty slide phone and had to wait till I was in grade 12 when I could afford to buy my own iPhone and by this time I was paying the bill too. My sister got her first phone in grade 8, mind you I had to wait till I was in the middle of grade 9. Her first phone? An iPhone of which my mom still pays the bill for and she's in grade 11 with a job. The day I got a job my allowance was cut and I had to pay my bill. My sister on the other hand still gets allowance and doesn't pay her phone bill. 
When I was in grade 10 I asked if I could go on the Europe trip in grade 11 with my school. My mom said no. I even offered to pay for it and she said no. But when my sister asked to go to Costa Rica my mom was all for it and even paid half of the trip. 
When I was 16 I started taking birth control, I didn't ask my mom because I could go to the doctors and do it myself, then my mom finds out and bitches at me saying I don't need it and how I'll screw up my body. But then when my sister turned 16 took her to the doctor to get it no questions asked. When I was 16 I wasn't even sexually active, it was literally for my period. My sister started having sex at 15 so you know it's okay for her to take birthcontrol. 
My aunt tries to justify it saying "times change and as a parent you learn over time". In 2 years things did not change so drastically that you give the younger child everything they want. 
I know I'm complaining and sounding like a brat but I honestly don't think it's fair that whenever I ask to do something or have something the answer is no but when my sister asks she gets it. I even offer to pay for my stuff and my mom still says no but goes and pays for sister to do it. 
Now my mom is having another baby and I honestly feel like I am going to resent him/her because I KNOW they will get spoiled rotten. I know it's horrible to feel that way because growing up my mom didn't have the funds to give us everything but now she does. She's already saving for the new baby to go to university but I am paying my own way through school. I even said why don't you save up money for all of your kids and split it. Yeah I'll be done school before the new baby goes to post secondary but I could put it towards my house or my family, etc. and she said "no, you'll have a job by then". It makes me so angry that this baby will have everything just given to them like that while I've been working my ass off to pay for school. And like my mom can't even justify why she gives my little sister everything she wants besides "well if you want it that bad you'll do it anyways" but then bitches at me for going behind her back and doing it. If you know I'm going to do it why not just allow me to do it in the first place because realistically you're going to let my sister do it. 
Anyways rant over. I don't care if you call me a brat or whatever. I'm just frustrated and it's upsetting that I feel like my mom favours my sister and let's her have everything she wants and that the new baby will have everything he/she wants as well.