Suddenly short period?

Normally I dont do this sort of thing but I’m trying to figure out of this is common. I always have very reliable periods. It’s starts right around when it’s supposed to and lasts for 6 days. I always have cramps leading up and sore breasts. The second and third day are ALWAYS the worst. Terrible cramps and very heavy bleeding. This period started a day late and I had no cramping before hand but sore boobs. I wouldn’t have thought anything of it but It was very light compared to normal and only lasted 2 days. Is this normal or has anyone else’s period randomly switched up like this? The only think I could thing of would be maybe I’m pregnant but I took a test this morning and it was negative....