I had sex with my partner last night; we used the pullout method and a little bit of cum was on (but not in) my vagina. Now today at about 3pm when I wiped, there was a very small amount of blood in clear discharge. My period is due in 3 days, but I've read this is around the time implantation bleeding would happen. But would less then 24 hours be too early for implantation bleeding? Is it more likely that it's an early sign of my period?