Irregularities/ Pregnancy possibilities *Sore Nipples*

Okay so ever since I stated getting my period it's been irregular. My Last physical period was in October, and lately I've been feeling really tired and hungry ( mostly craving junk food) but the most recent thing is that my nipples are extremely sensitive and sometimes sore. They've never been that way ever. I don't want to take a Pregnancy test too soon so when is the right time to take a test for a BFP !??