What Causes The Periods To Happen Only For A Day?

I am 28 and my husband is 30 we have been trying to get pregant for a year. Although he was told he has diabiets about four months ago. My friend saw me and told me that you are pregant I just blow her off. The next day my period start but it only last for a day and half when normal it is three days could these be a sign that i could be pregant?