3 days until period and I’m bleeding already 😔

I’m a bit confused, it’s 3 days early but it’s not like it normally is, I normally get really bad cramps the day before PLUS it’s really light, normally when I come on it is like a switch but it’s been 4 hours and it hasn’t even touched the pad!!! I’ve taken a strip test and it’s negative so I’m pretty sure it’s my period but I am a bit confused it’s normally the same old story with me so seems very odd that it is so different.