Could I be pregnant? Please help..?

Hi, i'm Harley Jo. Im 21 years old. My boyfriend and I are trying to concieve. For months we have talked about this, and have planned it; looking at it from all angles, and we have came to the conclusion that we want this. So, this month after i got off my period, which was May 26-31, we have had sex on June 3, 5, 8, 11, 12. Today, i noticed my breasts were a little sore, and i've been a little sick at my stomach. Do you think that i am pregnant, or is it more than 50% likely?.. We are so excited... And also, when is the earliest I can do a home pregnancy test, and it be accurate? Andy replies are deeply appreciated... Thanks so much..(: