Irregular Periods While on Birth Control: What to Know

Question
Hi, i have been on the pill for many years now, and over the years my period has become less in days of menstruation, but my last period was later than normal by 2 days and finshed at the same time so it only lasted for approx 1 1/2 days, the blood itself was barely there and very dark / dirty like in colour... is this normal behaviour after been on pill for so long? does this mean there could be a chance of being pregnant? should i be worried or just wait to see what the next one will be like, i have not skipped any pills and have continued taking them as normal.

Answer
Most women get lighter periods on the pill, and sometimes they are so light that they don't occur.  In other cases they will just be a little spotting, dark discharge like you've had.  Why it changes after being on the pill for years is unknown, but probably something else about your body has changed.  It is no cause of concern unless you think you might be pregnant.  Then I would do a test.  Otherwise wait and see how your next period is.  It happens more with some pills than others, so if it continues you can see your doctor to try a different pill, if it is bothersome.