Period, or pregnant?

Caitlin • I`m a married 30 y/o high school digital integration specialist. My husband and I welcomed our rainbow baby into the world 1/2017 and are excited to prepare to expand our family in the next few months.
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?
Does this seem like a pregnancy or a period?