is this normal?

I use tri-lo sprintec birth control pills, i've been on the pill for about 5 years. I would consider my period normal, but my last period was super weird. I didn't even need to use a tampon, only a liner. I've never had a period be this light before. Only really saw blood when wiping and a little in the morning on the liner one of the days. What does this mean? has anyone had any similar experience? is being pregnant a possibility?