Help? Period or implantation bleeding?


So my last period was July 12. According to <a href="">Eve</a> I was supposed to start on Aug 13. My period is 22 days late. I have had a little bleeding when me and my boyfriend do anything. Normally if I'm close to starting my period and we do anything I will bleed slightly and start my period the next day. The last week, I have bled a little after each time and I put in a tampon and there will be nothing? I have not taken a test yet because I have been disappointed so many times before. Any help or advice on what is going on? Or has anyone else experienced this?