Okay, So I Haven't Gotten My Period In About 5

Okay, so I haven't gotten my period in about 5 months and I thought I was pregnant at one point. I was sexually active for about a month. so I took three pregnancy tests one was positive other two were negative. but lately when I pee I only pee yellow and when I wipe there's sometimes blood. is there still a chance I can be pregnant? I'm 15 by the way.