Period, or pregnant?

Monday night my nipples started feeling super sensitive. Not painful but painfully sensitive. They're still feeling sensitive and the only time they've felt remotely close to this is when I was on birth control a couple years ago.  I noticed my beast are feel a little fuller and I started feeling slightly crampy last night and more so this morning. I'm not sure if I should take a pregnancy test because my period cycle is never consistent. Should I wait to take a test and see if it's just my period acting wacky?