Pregnancy symptoms, or? Help!

So lately as in like (two days in a row now) I've had a few weird cramps on and off.. Not period cramps. I start my period in 4 days so it's still to early to test. I've also had a headache and have just been crabby!! I've also experienced some nausea but through out the day not just in the morning. Just curious what's the first signs of pregnancy and am I just looking into something that's not anything?! Any advice would be helpful. Hoping at the end it turns out a + :)