Period 3 days late

Rebecca
Hey girls. 
I'm waiting for my period to come its 3 days late I took a test it came back negative 😪
I've had the cramps but just no period.. 
And a white discharge but other than nothing's happen. I do have endometriosis but it's weird for it to be 3 days late. 
Any ideas would be my hot appreciated 
Thank you 😘