What to think??

My cycle was suppose to come on the 19th. When it didnt, I took hpt. All were neg. I was hurtin in my lower abdomen, breast were sore, and I was nauseous. My cycle came on today(8 days late) but it's really light. I usually have heavy cycles. I haven't filled up a whole tampon. I know its the beginning but I saw the first sign of blood around 7 am. Any input?