Too soon to freak out!!!

Ok so my unpredictable period is M.I.A. It's too soon to tell if I am late or wasn't invited to the date change but it's freaking me out. It's more stressful not knowning anything. My period was orginally coming on the 5th of every month for about 4 months then changed last month to the 7th. So yesterday being the 7th my friend still hasn't arrived. Should I wait a week to test for pregnancy? Or is it to soon? I admit I tested last night and got a negative but again it may be too soon. Advice anyone?