Think I could be pregnant?

I am sleeping so much lately; I slept 14 hours yesterday. I am eating more and my boyfriend said my stomach is bigger (could be attributed to the food, I know, but I'm not a heavy eater usually; it's very abnormal for me to be eating in the quantities that I am). My breasts/nipples are sore and the veins on them are much more visible. Last week I had the worst headaches, dizziness, and nausea spells. I haven't had my period since the 14th of May, but my period isn't really regulated and kind of comes and goes when it wants. I don't know if these are symptoms of pregnancy, or signs that my period is coming...I feel like I may be psyching myself out. Advice?