So me and this guy I been seeing for 5 months been having unprotected sex for the past 2 months. In sept I had a period starting 16-21 and right the next day or two we had sex and he came inside of me. Then on October 2 we had unprotected sex again but we used the pull out method. My calculator said I was firtile from 3-7 of October. Now I'm expecting a period the 15 but it changed because I calculated that my cycle were 33days not 30 like I thought so it pushed my period back to the 19 of October. On the 11th of October I noticed a little bleeding reddish then just brown spotting on and off mostly when I wipe that continues till today. I took a pregnancy test on the 13th that came out negative and another one today the 15th that also came out negative. I don't feel any tenderness on my breast but I do feel little cramps and some back pains and on and off headaches. I'm so confused please help!

P.s I have been a little stress also