Light Spotting After Period: Causes & What to Watch For

Question
The first day of my last period was about 3-4 days before thanksgiving.  I am 32 with a 3 year old. I am writing to you because for the last 7 (it seems to have ended today) days I have had a very light dark brown spotting. I have never spotted in between periods and am concerned. I am not trying to get pregnant and shortly before I began spotting I had an xray of my spine. Could this be a miscarriage? Could I be pregnant and the spotting is from implantation?   I did have sex with my husband shortly after my period. When can I take a pregnancy test to find out for sure? If I am pregant, could an X-ray have caused  damage in the first or second week of conception?  Please help...

Answer
If your last period started on November 22, and you have a normal 28 day cycle (from the first day of your period until the first day of your next period) ovulation probably occurred on December 5. Often you can get some bleeding at the time of ovulation (mid cycle bleeding). You could have become pregnant if you had unprotected sex on December 4,5,6, or 7. If you did become pregnant on one of those days, a pregnancy test would not show a positive result until 14-21 days later. The best time to take a pregnancy test is seven days after you miss your next period. You are due for your next period on December 19. Therefore, if you do not get your period by then, wait an additional week and take a pregnancy test. You could not have become pregnant before December 5, so if you had the X-rays before then, there is absolutely nothing to worry about.