Pregnant or Plan B?

Hey y’all, so I had sex and the guy came in me , but I took a plan b the next day, and got my period the next week, the next month went by and NO PERIOD, so this month came by and I got my period for about two days . Now mind you I have taken pregnancy test and they have all came out negative ! Now I look at my stomach and see that there is a faint line on my abdomen to my belly button! AM I PREGNANT ?