Possibly pregnant?

I haven't been pregnant before so I don't know what to think. I've had my cycle for the past two months as normal, but the only difference is I normally cramp a lot during them and they're usually a lot heavier than these two. For the past couple weeks, I have been extremely nauseous, sleepy (mind you, I always get a full 8 hours, and still feel sleepy at work), and craving weird combinations of foods. For these weeks, I always want salty food mixed with something sweet together. I don't know what to think. I'm nervous to take a pregnancy test, because I don't know whether this is in my head or is there a possibility I actually could be pregnant. I also know that sometimes the ovulation charts could be off a little. I have mines posted for these past two months. Thanks in advance!