Too much Sleep

Hi! This is my first post so please be nice to me :). I (21 female) can sleep all day everyday if I wanted to. Is this normal? When I wake up I feel irrationally angry and just want to sleep all the time. I slept 12 hours last night and just woke up from a 4 hour nap and feel like I could go back to sleep. Should I go to the doctors or do I just need more self discipline?