I have been on kariva birth control for about 3 months now. The only side effects I have regularly had was gas pains. 2 weeks ago I had sex with my boyfriend 4 times in about 2 hours. A little while after that I have been nauseous, having back pains, headaches, sleeping alot during the day but tossing and turning during the night. I have also felt really hungry constantly but when I try to eat I can't eat too much before I feel sick. It would only be 2 weeks after conception. Could I be pregnant?