Weird "period".

My cycles have always been 25 days and my periods are heavy on days 2 and 3 with lots of clots and last 5 days. Well, this month, I was 3 days late and my bleeding only lasted 3 days, was lighter than normal (I usually go through a whole box of tampons but only used 4 this month), and never passed any clots. Has anyone ever had a similar situation and actually ended up pregnant? I have never had a light period so It's got me wondering.