Love my little sis but need to rant!

Chelsey • 27, happy wife of 4 years and I love my job! Due 5/28/15 with #1!
So my sister, who's 6 yr younger than me, just announced she might be moving her wedding from summer 2016 to next year! She's a senior in college currently and won't be completely finished until next Fall, plus she's working three jobs! I have no idea how she will manage it. I'm matron of honor, which I'm very excited about, but I now feel like her wedding plans are going to completely over shadow my pregnancy and my parents' excitement for their first grandchild. We aren't ready to tell them yet, we have a surprise planned in a couple weeks when we celebrate my dads birthday and we are all together. Knowing her she will likely have set a date and booked the venue by then! And I can't help but wonder of she wouldn't be planning this if she knew. I feel selfish but as my first pregnancy and the first baby in my immediate family, I want the attention for once! Am I just overly emotional because of hormones or what??