Hmm. You may just be sick. I didn't feel any symptoms when my first period swung around, but now, almost three years later, I have such terrible cramps that I cry and just sit in my bathroom bleeding. And that's a lot coming from me since I have a high pain tolerance lol. Actually last week they got so bad, as usual, I searched up on youtube some quick methods to help with period cramps! And I found this lady showing yoga practices to help, so I need them, and my cramps were gone. However I still had a horrible headache that made me feel like my scalp was being pulled back. Anyways point is, usually for almost all cases of first periods you won't feel anything.