Hi. Lately this month I've been excersising hard such as conditioning and weightlifting for 4 hours a day. I am 15 years old and I had sex for the first time last week but it was protected and I missed my period by 6 days. My uterus has been twitching constantly ever since and It feels like period cramps and bloating. What can be the cause of this? Did I damage anything in my body? I can't be pregnant right?