The breasts could be a sign, but if your not even due your period until next week, that seems a little early to be getting breats tenderness. I have had 3 children and have never gotten discharge from my breasts until very late in pregnancy. But everyone is different. As for sleeping, yes being sleepy is symptom of early pregnancy but usually not until you are at least 6 weeks, which you would only be 3-4 weeks (1st day of last period is when you start the age of pregnancy). I believe sleeping so much makes you sleepy. It is a fact that people who sleep alot tend to need more sleep and become lethargic. Diet can attribute to this and frankly, so can not doing anything. Other tell tale signs to watch for would be cramping, sort of like a period that just won't start. Occasional dizziness, like tunnel vision, possibly only once when standing up fast or aversions to certain smells, moreson than normal. Its early to tell, but there are some tests that will detect a pregnancy very early. If you test and it is negative wait until a week after you have missed your period, then test again. I suggest you go to a clinic, and get a blood test, and just find out now. The breast issues may be a sympton of something else. Medication, birth control, hormone issues...If you have taken anything. Good luck, don't stress, and try only sleeping from 11-8 for a few days. I guarantee you will feel better whether you are pregnant or not!
Good luck!!