Not sure what's going on..

So I posted a few days ago just about the fact that my period isn't due until next week but for the past few days I have had some period - like cramps. I've also had sore breasts (which is very uncommon for me. Even before and during menstruation ) my breasts have been swollen for what seems like forever. I have never been pregnant so I am not sure if this is a possibility or not. I have not had any spotting at all, and in the past I have had ovarian cysts. I am unsure if there is a health issue to worry about or if it's possibly pregnancy. Also, when should I test for pregnancy? I am due next week, and I know it's not accurate when you test too soon. Has anybody ever had symptoms like this? If not, what were some very early signs of pregnancy for any of you ladies? Thank you all so much for your time !