please give me some advice

Sooo. That last time i had sex was the 5th of may goin into the 6th of may lol. I started ovulating on the 6th. And no he didnt cum inside of me but heres the tricky part. Two days ago i started tasting metal in my mouth. Im due to get my period this upcoming wednesday which is the 24th. But anyways i was tasting metal in my mouth a couple of days ago and olus it felt like my period was tryin to come so i put a tampon in just in case. The next day before i showered i tool the tampon out and it was a lil blood on there kinda dark not much. Thats when i started to freak out. I took two pregnancy test and both came out negitive.  So last night i put a tampon in and his morning when i took it out there were lil specs of blood on it again not much. What could possibly be going on yall? Please help because im scared as hell. I have a doc appointment tomorrow to take another test. But again my period is suppose to come this upcoming wensdey. Couldnit just be because my period coming or am i pregnant. No im not feeling sick nor do i have any other symptoms.