Ideas? Reasons?

Okay so my boobs have been hurting for about 2 weeks. (It's totally normal for them to hurt a week before my period. I'm about 7 days till. So they started a good bit early) and Ik that is a symptom of pregnancy. Also the past 3 days I have been cramping. I've been nauseated also. But I've been feeling nauseated for 2 months. I haven't thrown up at all though. I did have my period last month. So idk what all of this means. I'm planning on buying a pregnancy test. Don't you have to wait till you are close to your period though? I have no idea what to think. I know nothing about this stuff. Please help.