Spotting before your period.

I went to my obgyn on Tuesday for my yearly pap. I asked for a pregnancy test cause I had sex while I was ovulating. Well it was neg. Yesterday I thought I got my period cause I'm suppose to get it today anyways. No just brownish spotting and it's really only when I wipe. I've never had this before a period. Only after I end typically. Today I get my period but I it's normally never on time. Either late or early. So is there a chance I could be pregnant? Even tho the drs test was negative?! I'm freaking out over here.