What gives pregnant or period?

ok posted before my period was a week late and last night i had a light pink bleeding, so i was like dang, my period so i waited through the night, didnt bleed all night long, got up this morning, had more light pink bleeding so i put a tampon in and went to school, got home and changed it, sorry if tmi, but it was barely anything, so i was like ok, i put in a nother to be safe, just changed it again and it waas barely nothing again im having what feels like major cramps but im barely bleeding is it just a light period but if so why the major cramps????