Spotting or Period?

So I have been on the pill for about 4 months now. i switched my time last month and it threw me off. i just took my first white pill last night and i am super crampy today and tired and i can't tell if it's my period or spitting? but it feels like too much to be just spotting. could it just be that or is it possible that i have my period after starting the white pills? according to eve i'm not supposed to get my period for 19 days. help!!!