I'm 19 And A Virgin; However, I Missed My Period

I'm 19 and a virgin; however, I missed my period last month and this month ( I'm pretty regular) I keep thinking I'm pregnant. I masturbated while over a toilet and my vaginal fluids touched the toilet water and I was thinking that if there is sperm in the toilet, it could somehow swim up the fluid and cause pregnancy. I also feel like I'm experiencing pregnancy symptoms. What is happening to me?