Extra emotional when I have sex before my period 😕

Okay, recently I've been realizing that when I have sex between cycles the 2-3 days before my period I am extremely emotional like every little thing I just start crying not like a little tear but like big rain drop tears and it could be for anything. But I only get like that when I've had sex when I don't have sex for a while I just start my period without any emotions. I'm just curious to know why does that happen 😟