Spotting after sex

Why when I have sex I bleed after? I recently stopped my birth control so my period has been kinda irregular. The end of feb, beginning of March I had my period for 2 weeks straight and it went away. I had sex today after 3 days of not having my period and now I am bleeding again with cramps and cravings as if I was getting my period. Is this because I’m recently off of my birth control?