What Is The Nausea And Fuller Breasts After Having Unprotected Sex?

Yeah i have had unprotected sex for about a month and a few weeks maybe less and i have been nausiated not only in mornings but in the middle of the day and night, But its not every day. My boobs have developed stretch marks over the last month or so and when im not nausiated i think about it and i end up puking, I been on depo provara the birth control shot and i have needed another one but havent got around to it but some days ill feel pregnant and some days normal, My boobs arent that sore at all and i dont have a period so i cant tell but i have been urinating more then usual and i have always had constipation my whole life but now in the past month or so i have been going number to way more often and easier then normal I have fatigue and im tired more help me out? what should i do?