Period stopped than started

Okay so this Sunday my period started and by Tuesday night ( yesterday) I was just spotting l. Before bed i put a pad on woke up to nothing went to the bathroom multiple times thru out the day and nothing even when I wiped so I took my pad off since it was “done” and than my SO and I had sex on our white sheets and nothing so I defiantly knew we were in the clear now hear I am 3 hrs after laying butt naked on our white sheets with no problems and than I started bleeding again?! What the hell? Like it wasn’t a drop either it was a good amount like the size of a silver dollar. I have had it where I barely spot but not stop than start so confused right now how do I go all day with nothing have sex and nothing and than bam I sttt bleeding ?!