Why do I feel like this?

My obgyn put me on provera 10mg for 5 days because I haven't had my period for months and months. I finished my provera and it has been 3 days since my last pull, for the last few days I've been feeling so weird. I'm super sleepy all the time, my boobs got bigger and my nipples are so sore, touching them hurts. I took a pregnancy test which was negative. Any thoughts why I might be feeling like this?