I'm 22 I had sex twice in one night with my boyfriend a day before my fertility window which was Dec 4th. I started to have a little cramping around the third day of my fertility window. Yesterday and today I've has nausea and cramping. Right now I'm having bad cramps which I never usually experience unless it's my first day of my period and i only sometimes get them. I'm confused and I took a test yesterday and it was negative. Please leave a comment!!!