Someone Please Tell Me If This Sounds Like I'm Pregnant

So I had my son August 9th, 2011 and got my tubes tied the same day.  I had my period for like 2 weeks then had intercourse and then went to the doctors for my check up with a pap.  Everything came back normal.  The middle of September I had brown discharge for a couple days then had my period for a 5-7 days.  Same for October and November.  Then the first week of December I only had the brown discharge as normal and expected my period to follow but got nothing.  December 31st I had intercourse then had light pink discharge the next day, then had intercourse again that night and had more light pink discharge on January 2nd, 2012.  So I got worried as I have been because none of this is normal for me at all and called my doctor January 3rd, 2012 and she suggested that it might be too early for me to get my period.  To wait til the 15th and if still nothing to call back.  January 5th I started what I think was my period but it only lasted for 3 days which isn't normal either for me.  Then about three days later I had the same brown discharge then had intercourse again that night nothing the next day.  Then January 19th & 20th I had the brown discharge and again on the 22nd.  Has anyone experienced this if so what was the result?  I'm not worried about an STD because there's no odor, it doesn't itch and doesn't hurt to have intercourse.  I am going to the doctors to get a blood test done but wanted to see if anyone else has had this same experience.