SD, I know exactly how you feel -- there's something about those mid-20s and that season of life when everyone around you gets married then thinks you too should be married. Stick to your guns - you're in no hurry, you have a great life, you love your life, and you know that God knows what is best, far better than you or any of your well-meaning friends do.
That being said - some strategies for combating this -- come up with some interesting answers to those intrusive questions .. 'I would get married but this would jeopardize my standing with the CIA - they're trying to save money, ya know and have you seen the price of background checks these days??? Not to mention two of them???' Folks on this board could come up with some far better 'reasons' why you aren't married yet -- I'm no match for their wit. The more far-fetched the reasons, the easier it will be to laugh then hastily change the subject to less annoying topics.
Then plan something really fun to do after those weddings -- if they involve a weekend out of town then plan something for the weekend after - something unique to what you love to do and with friends/family that you love. Looking forward to something will remind you that your life, as an unmarried person, is full of meaning and that, married or not, you have a dazzling future ahead of you. And one of my favorite things about not being married is that I get so many great opportunities to spend time with my friends, without the added complications of a husband or children.