Am I pregnant? Please help?

I have been with my boyfriend for almost two years and have been having sec pretty much the whole time. Unprotected. And I have never gotten pregnant. However. I had sex with another man on the sixteenth. I usually get my period on the second of every month. Since the sex I have developed a yeast infection. Been nauseated. Vonstatly eating but I'm not at all hungry, my hair has been greasy and I felt a grape sized ball in my vagina towards the back. I have also been VERY bloated. I took a test 14 days after conception and it was negative. Am I pregnant?