Confused: Needing a little more advice.

I posted on here earlier about a weird period I had this month. Everything seemed normal the week before as far as symptoms. But I was two days late which didn't really worry me, but when my period finally came I only had light bleeding in the morning and it lasted a little more then half the day. Usually I have a reallgular in every way 3-4 day period. 
I ask if this was anything to worry about, and I was told to take a pregnancy test or that the bleeding could be implantation bleeding. 
I guess I would just like some more thoughts before I go buy a test. 
Thank you